Buying the X-T2 or the X-T20

Although these two cameras share the same lens stable, sensor and processor there are some items that do vary, when you compare specifications. However, this does not really tell the whole story, and necessarily help you decide which camera to buy.  So the following are a few general scenarios that might help focus your decision.
Budget Conscious 
If you are on a budget and getting into Fujifilm equipment for the first time, the X-T20 might be a better choice than the X-T2. In this kind of a situation, one usually acquires a kit lens with the camera and often this means you do not have enough money left to buy a prime lens. This leaves you shooting with a zoom lens without the advantages of a prime lens. If you buy the X-T20 over the X-T2 kit you would saving $800 CAD. There are two possible kits with this camera and I would suggest the 18-55 f2.8-4 over the 16-50 f3.5-5.6, the former being a much faster lens. In fact, it is one of the fastest kit lenses I have seen on the market. This $800 saving could be applied toward a 55-200 f3.5-48 lens if you are committed to zoom lens shooting or could go toward a fast XF 35mm f1.4R prime.
Choosing the X-T20 over the X-T2 would mean sacrificing the dedicated ISO dial, the weather proofing, the dual high speed card slots, the three-way articulating LCD and some other items listed in the specifications list below, but this may not be a deal breaker as you also gain a few things. First, it is a smaller and lighter camera, has a built-in flash and its articulating LCD has a touchscreen instead of the three-way LCD.
As a Backup Camera
If you are thinking of a backup camera this might also be a better choice over the X-T2, as you likely have already invested in either X-Pro2 or the X-T2. This smaller camera, provided you are not in inclement weather, gives you an option of a more discreet camera for the street. It also makes an even better companion to the X-Pro2, which does not have an articulating screen, for those over the head or close to ground shots. After all age or mud sometimes makes it impossible to get down low enough to either see the LCD on the X-Pro2 or look through its viewfinder.
As an Upgrade From a DSLR
If you are moving across from a DSLR to the mirrorless world then the X-T2, in most cases, would be a better choice, as this Fujifilm camera is so much smaller than any DSLR on the market. If you are shooting with a lower end DSLR, like the Nikon D5600, the addition cost of this camera buys you an upgrade that has a lot of the features of a D500, and the image quality of the full frame D750 (unless you are shooting at very high ISOs), at a lower price and in a smaller package. So you would not only be moving across but upgrading to a feature rich camera with better image quality.

Image from camerasize.com

Like the D750 the X-T2 has a magnesium alloy body, the same autofocus choices, dual high-performance SD slots, however, the Nikon only has 51 focus points compared to the 325. The X-T2 has a three-way tilting LCD compared to the Nikon's two-way, with it's small size the LCD is .2mm smaller, which is not really significant. The viewfinder on the Fuji camera, however, has a stunning resolution of 2,360,000 and 100% cover unlike the Nikon. One of the big gains with the Fujifilm camera is the shutter which can be set to complete silence and with a maximum speed of 1/32000 compared to Nikon's slapping mirror with a top speed of 1/4000. This means when you shoot with the Fuji camera on silence unlike the Nikon camera you hear absolutely nothing.
The lack of a mirror and silent electronic shutter does make for reduce the risk of vibrations when the camera is on the tripod for slower shots, and if you are trying to capture fast moving objects the Fujifilm camera's 14 frames per second speed is more likely to produce better results than the 6.5 frames per second on the Nikon camera.
Bracketing on the Fujifilm camera is limited to three frames at a maximum increments of two stops, whereas the D750 has up to seven brackets at a maximum of two stops; with the advancements in sensors and high dynamic range processing, this difference may no longer be an important issue, and certainly I have not found this a problem since selling my Nikon equipment.
One of the secrets of shooting mirrorless over DSLR is the viewfinder shows the jpeg! In other words, before you press the shutter, you can see what you will be getting. This allows you to avoid shooting a series of shots before checking the LCD only to find your settings were all wrong. In addition to this, you can correct the jpeg's exposure and see the adjustment results in the viewfinder prior to taking the shot.
Finally, there is the replacement of a digital read out on the Nikon cameras with real dials, especially on the X-T2 where it has a separate dial for ISO and Speed, with the aperture settings on the lenses. Although this appears at first to be a "retro" look and perhaps cosmetic, it does, in fact, make the camera easier to operate and a pleasure to use. The X-T2 as a result quickly melts into the background as you concentrate on your photography.
Comparing X-T2 Specification to the X-T20

camerasize.com

Model and Price	FUJIFILM X-T2 $1950 CAD (with 18-55 f.8-4OIS lens $2400)	FUJIFILM X-T20 $1200 CAD  (with 18-55 f.8-4OIS lens $1600)
Effective pixels	24.3 million pixels
Image sensor	23.6mm x 15.6mm(APS-C)X-Trans CMOS III with primary colour filter. Sensor Cleaning system Ultra Sonic Vibration	23.6mm x 15.6mm(APS-C)X-Trans CMOS III with primary colour filter. Sensor Cleaning system Ultra Sonic Vibration
Storage media	SD Card (-2G) / SDHC Card (-32G) / SDXC Card (-256G) UHS-I / UHS-II	SD Card (-2G) / SDHC Card (-32G) / SDXC Card (-256G) UHS-I
File format	Still image: JPEG (Exif Ver.2.3), RAW: 14bit RAW (RAF original format), RAW+JPEG Movie Mod MOD: Movie Video Compression: MPEG-4 AVC / H.264 Audio: Linear PCM/ Stereo sound 48KHz sampling
Number of recorded pixels	L: (3:2) 6000 x 4000 / (16:9) 6000 x 3376 / (1:1) 4000 x 4000 M: (3:2) 4240 x 2832 / (16:9) 4240 x 2384 / (1:1) 2832 x 2832 S: (3:2) 3008 x 2000 / (16:9) 3008 x 1688 / (1:1) 2000 x 2000
Lens mount	FUJIFILM X mount
Sensitivity	Standard Output Sensitivity: AUTO1 / AUTO2 / AUTO3 (up to ISO12800) / ISO200 to 12800(1/3 step) Extended output sensitivity: ISO100 / 25600 / 51200
Exposure control	TTL 256-zone metering, Multi / Spot / Average / Center Weighted
Exposure mode	P(Program AE), A (Aperture Priority AE), S (Shutter Speed Priority AE), M (Manual Exposure)
Exposure comp.	-5.0EV - +5.0EV, 1/3EV step (movie recording : -2.0EV - +2.0EV)
Image Stabilizer	Only with OIS type lenses
Shutter type	Focal Plane Shutter
Shutter speed	Mechanical Shutter 4 sec. to 1/8000 sec.(P mode), 30 sec. to 1/8000 sec.(All modes) Bulb mode(up to 60 min), TIME : 30 sec. to 1/8000 sec. Electronic Shutter*3 30 sec. to 1/32000 sec.(P / A / S / M modes) Bulb mode : 1 sec. fixed, TIME : 30 sec to 1/32000sec. Mechanical + Electronic Shutter 4 sec. to 1/32000 sec.(P mode), 30 sec. to 1/32000 sec.(All modes) Bulb mode(up to 60 min), TIME : 30 sec. to 1/32000 sec. Synchronized shutter speed for flash 1/250 sec. or slower	Mechanical Shutter 4 sec. to 1/4000 sec.(P mode), 30 sec. to 1/4000 sec.(All modes) Bulb mode(up to 60 min), TIME : 30 sec. to 1/4000 sec. Electronic Shutter*3 4 sec. to 1/4000 sec.(P mode) 1 sec. to 1/32000 sec. (P / A / S / M modes) Bulb mode : 1 sec. fixed, TIME : 1sec to 1/32000sec. Mechanical + Electronic Shutter 4 sec. to 1/32000 sec.(P mode), 30 sec. to 1/32000 sec.(All modes) Bulb mode(up to 60 min), TIME : 30 sec. to 1/32000 sec. Synchronized shutter speed for flash 1/180 sec. or slower
Continuous shooting	Approx. 14.0 fps [Only Electronic Shutter](JPEG: 42 frames, Lossless compression RAW: 28 frames, Uncompressed RAW: 25 frames) Approx. 11.0 fps [Only with Electronic Shutter] (JPEG: 73 frames, Lossless compression RAW: 30 frames, Uncompressed RAW: 27 frames) Approx. 8.0fps (JPEG: 83 frames, Lossless compression RAW: 33 frames, Uncompressed RAW: 27 frames) Approx. 5.0fps (JPEG: endless, Lossless Compression RAW: 39 frames, Uncompressed RAW: 30 frames) * recordable frames depends on recording media * Speed of continuous shooting depends on shooting environment and shooting frames	Approx. 14.0 fps [Only Electronic Shutter](JPEG: 42 frames Lossless compression RAW: 23 frame Uncompressed RAW: 22 frames) Approx. 11.0 fps [Only Electronic Shutter] (JPEG: 56 frames Lossless compression RAW: 24 frame Uncompressed RAW: 23 frames) Approx. 8.0 fps (JPEG: 62 frames Lossless compression RAW: 25 frame Uncompressed RAW: 23 frames) Approx. 5.0 fps (JPEG: 68 frames Lossless compression RAW: 28 frame Uncompressed RAW: 25 frames) Approx. 4.0 fps (JPEG: 73 frames Lossless compression RAW: 29 frame Uncompressed RAW: 25 frames) Approx. 3.0 fps (JPEG: 81 frames Lossless compression RAW: 32 frame Uncompressed RAW: 27 frames) * recordable frames depends on recording media * Speed of continuous shooting depends on shooting environment and shooting frames
Auto bracketing	AE Bracketing(±2EV / ±5/3EV / ±4/3EV / ±1EV / ±2/3EV / ±1/3EV)  Film simulation bracketing(Any 3 types of film simulation selectable)  Dynamic Range Bracketing (100% · 200% · 400%) ISO sensitivity Bracketing (±1/3EV / ±2/3EV / ±1EV)  White Balance Bracketing (±1 / ±2 / ±3)
Focus	Mode: Single AF / Continuous AF / MF type: Intelligent Hybrid AF (TTL contrast AF / TTL phase detection AF) AF frame selection: Single point AF: EVF / LCD: 13x7 / 25x13 (Changeable size of AF frame among 5 types),  Zone AF: 3x3 / 5x5 / 7x7 from 91 areas on 13x7 grid, Wide/Tracking AF: (up to 18 area) * AF-S : Wide
White balance	Automatic Scene recognition, Custom1~3, Color temperature(2500K~10000K)  Preset: Fine, Shade, Fluorescent light (Daylight), Fluorescent light (Warm White), Fluorescent light (Cool White),Incandescent light, Underwater
Self-timer	10sec. / 2sec.
Interval timer	Yes (Setting : Interval, Number of shots, Starting time)
Flash modes	FLASH MODE: TTL (FLASH AUTO / STANDARD / SLOW SYNC.) / MANUAL / COMMANDER / OFF (When EF-X8 is set) SYNC. MODE: 1ST CURTAIN / 2ND CURTAIN / AUTO FP(HSS)
Hot shoe	Yes (Dedicated TTL Flash compatible)
Viewfinder	0.5 inch approx. 2.36 millions dots OLED Color Viewfinder Coverage of viewing area vs. capturing area: approx. 100%  Eyepoint: approx. 23mm (from the rear end of the camera's eyepiece) Diopter adjustment: -4~+2m-1 Magnification: 0.77x with 50mm lens (35mm equivalent) at infinity and diopter set to -1.0m-1  Diagonal angle of view: approx. 38° (Horizontal angle of view: approx. 31° )  Built-in eye sensor	0.39-in., approx. 2,360K-dot OLED color viewfinder, Coverage of viewing area vs. capturing area : approx. 100%  Eye point : approx. 17.5mm ( from the rear end of the camera's eyepiece), Diopter adjustment : -4m ~ +2m-1(dpt)  Magnification : 0.62x with 50mm lens(35mm format equivalent) at infinity and diopter set to -1m-1.  Diagonal angle of view : approx. 30°( Horizontal angle of view : approx. 25°) Built-in eye sensor
LCD monitor	3.0 inch, aspect ratio 3:2, approx. 1,040K-dot, 3 way tilt	3.0-inch, aspect ratio 3:2, approx. 1040K-dot 2 way tilt
Movie recording	[4K (3840x2160)] 29.97p / 25p / 24p / 23.98p 100Mbps up to approx. 10min. [Full HD (1920x1080)] 59.94p / 50p / 29.97p / 25p / 24p / 23.98p 100Mbps up to approx. 15 min. [HD (1280x720)] 59.94p / 50p / 29.97p / 25p / 24p / 23.98p 50Mbps up to approx. 30min.
Film Simulations	15 modes (PROVIA/Standard, Velvia/Vivid, ASTIA/Soft, CLASSIC CHROME, PRO Neg.Hi, PRO Neg.Std, Black & White, Black & White+Ye Filter, Black & White+R Filter, Black & White+G Filter, Sepia, ACROS,ACROS+Ye Filter, ACROS+R Filter, ACROS+G Filter)
Dynamic range	AUTO, 100%, 200%, 400%
Advanced filter	Toy camera, Miniature, Pop color, High-key, Low-key, Dynamic tone, Soft focus,Partial color (Red / Orange / Yellow / Green / Blue / Purple)
Wireless transmitter	Standard: IEEE 802.11b / g / n (standard wireless protocol) Encryption, WEP / WPA / WPA2 mixed mode Access mode: Infrastructure
Wireless function	Geotagging, Wireless communication (Image transfer), View & Obtain Images, Remote camera shooting,PC Autosave, instax printer print
Terminal	Digital interface USB3.0 (High-Speed) / micro USB terminal * connectable with Remote Release RR-90 (sold separately) HDMI output HDMI micro connector (Type D) Others ø3.5mm, stereo mini connector (Microphone) / ø2.5mm, Remote Release Connector Hot shoe, Mechanical release shutter button	Digital interface USB2.0 (High-Speed) / micro USB terminal * connectable with Remote Release RR-90 (sold separately) HDMI output HDMI micro connector (Type D) Other Φ2.5mm, stereo mini connector Microphone
Power supply	Approx. 340 still frames using XF35mm F1.4 R set to LCD monitor on. Battery life in movie capture with Face off in 4K: approx. 40 min., full HD approx. 50min.	Approx. 350 still frames using XF35mm F1.4 R set to LCD monitor on. Battery life in movie capture with Face off in 4K: approx. 50 min., full HD approx. 60min.
Dimensions	132.5mm (W) x 91.8mm (H) x 49.2mm (D) (minimum depth 35.4mm)	118.4mm (W) x 82.8mm (H) x 41.4mm (D) / 4.66in. (W) x 3.26in. (H) x 1.63in. (D) (Minimum Depth : 31.9mm / 1.3 in.)
Operating Temp.	-10°C - +40°C	0°C - 40°C
Weight	Approx. 507g with battery and SD card	Approx. 383g with battery and SD card
Operating Humidity	10 - 80% (no condensation)
Starting time	Approx 0.3sec.	Approx 0.4sec.
Accessories included	Li-ion battery NP-W126S Battery charger BC-W126 Shoe-mount flash unit EF-X8 Shoulder strap Body cap Strap clip Protective cover Clip attaching tool Hot shoe cover Vertical Power Booster Grip connector cover Sync terminal cover Owner's manual Warranty+D66	Li-ion battery NP-W126S Battery charger BC-W126 Body cap Shoulder strap Metal strap clip Protective cover Clip attaching tool Owner's manual

X100F Announce by Fujifilm

January 19, 2017, Fujifilm announced their new upgrade to the X100 series, they are calling it the X100F as it is the fourth iteration of this camera. However, it is a considerable upgrade over the last three models, the last one being introduced int 2014. The biggest change is the sensor which like the X-T20, X-T2 and the X-Pro 2 has moved from 16 megapixels to 24 megapixels increasing the resolution significantly. In addition to this, the sensor is using a copper substrate rather than aluminium which decreases the noise level coming from the camera getting much better performance at high ISOs.

FUJIFILM X100F 

X100F Compared to the X100T
New Dial Configurations
There are also some important differences in the ergonomics of the camera starting with the external controls. First, the camera has used the retro style ISO dial build into the speed dial like you would find on older film cameras, although very elegant it is not a practical as the method employed on the X-T2 but it is in keeping with the "retro" style of the camera. The exposure compensation dial has also been modified to allow for a "C" position which allows the camera to go beyond the three stop plus or minus adjustment to five stops. On the back of the camera, you will find the buttons have been all been reconfigured onto the right-hand side making it much easy to make adjustments with your right thumb. But the best change is in this array is a focus lever the "focus lever" which is also found on the X-T2 and X-Pro2. It allows for very quick adjustments in selecting the autofocus point. I think this is one of their best innovations to date.
Other Changes
Another change that does not show up in the specifications is the drive modes. Typically Fujifilm cameras have had two ways to set the continuous drive basically fast and slow. This camera has introduced four modes of continuous drive 3fps, 4fps, 5fps and 8fps, something that will be extremely useful in shooting portraits and taking action shots.
The camera, of course, includes the expanded jpeg engines which include Provia, Velvia, Astia, Acros, Classic Chrome, Pro Neg Hi, Pro Neg. Std, Monochrome and Sepia. If you are used to shooting RAW plus jpeg, you will likely have noticed that sometimes the jpeg results are often hard to reproduce when processing a RAW file, and often so good that you can simply use the jpg and "bank" the RAW file.
Specification Changes
The chart below highlights only the differences between the two cameras and overlooks any specifications that remain the same.

Looking at this list the important change, of course, is the sensor, the processor and the resulting improvements in high ISO image quality. The change in auto exposure bracketing will also be a welcome change for those who work with a wider dynamic range in their images. 

Unique Features to the X100 Cameras
The camera has a built-in neutral density (ND) filter a feature that is an asset when shooting wide open in bright light or if you are taking slow shutter shots. This ND filter cuts down on three stops of light. Like previous versions of this camera one can acquire conversion lenses something that some shooters will appreciate. It also still has the famous hybrid viewfinder that allows either an optical or electronic viewfinder at the flick of a lever. Like other Fujifilm cameras when focusing manually you can either use focus peaking or the digital split screen method. The camera also has a macro setting for shooting as close as 10cm like the previous models, however the literature now says this is automatic in the new model.
Conclusion
This is a great upgrade to the X-100 series and brings it into line with the X-T10, X-T2 and X-Pro2 one can only hope the next upgrade will be the X70 gaining the 24-megapixel sensors that these three cameras now have. One can not avoid observing that if the quality of the 23mm (35mm format equivalent to 35mm) lens in this camera is either equivalent to the XF23mm F2 lens or better, carrying this camera with your existing X-T2 or X-Pro2 kit might be an option, rather than carrying that lens. Especially when you see how much smaller this camera is when compared to the other two with their lens on. Seems to me it would almost fit into the same space where my 23mm lens currently lies.
There are of course always things you feel would make the camera better such as an articulating LCD, a better cup around the viewfinder or the toggle on off dial locks found on the X-T2, but this does not take away from the elegance and usability of the camera. Like the X-T2 and X-Pro2 it will no double be a please to use and that is also, I think, important when picking a camera. If a camera is a pleasure to use then it melts into the background so you can concentrate of the pleasures of photography.

Fujiflim and Hasselblad's Bid for the Medium Format Mirrorless Market

The medium format cameras have been traditionally considered a studio camera, although that is far from the real truth as there are lots of accomplished artists using this camera in the field, one only has to look at the work of Edward Burtynsky. He like many others has flown these cameras on quad copters, pointed them out of helicopters and aeroplanes, and off of temporary platforms or ladders. Removing the mirror out of these cameras should create a lighter more portable camera, that will expand what can be done in the field. The two diagrams below which compare the GFX and X1D mirrorless to the 645Z illustrated this difference. Perhaps this is what is behind DJI's, a very successful drone manufacturer, acquisition of a majority stake in Hasselblad, they see the potential of using these cameras on drones.

Photograph Comparison from FujiRumors

Photograph Comparison from FujiRumors

Is it Really Medium Format
Medium format cameras have various sizes of sensors unlike APSC and full frame (with the exception of Canon sensors of course) they are standardised sizes. The following illustration gives you a good idea of the size of the sensor in these two cameras and how they compare.

As you can see although the sensor is similar in size to the Pentax it is significantly smaller than the traditional Hasselblad sensor. However, if you do the math the full frame sensor is 60% the size of the GFX 50S/X1D sensor, which is also a significant difference. Two Very Different Approaches
Two companies have recently developed medium format mirrorless cameras. Hasselblad announced the X1D in June of 2016 with a 50MP CMOS sensor (43.8 by 32.9mm) then Fujifilm announced the GFX 50S with a 51 megapixel CMOS sensor (43.8 by 32.9mm). They have each taken quite a different direction in their approach developing the mirrorless medium format camera. I suspect this difference means that it is impossible to suggest one is better than another as neither will appeal to the same sort of photographer.
The X1D smaller in size and also 75 grammes lighter so it will appeal more to a photographer to those who currently own a large mirrored medium format camera or as an upgrading to the owner of s full frame high-resolution mirrorless camera, and want a good lightweight field camera.
The GFX 50S, on the other hand, is larger and heavier but has the advantage of adapting other medium format brand lenses, including the Hasselblad leaf shutter lenses. It also unlike the Hasselblad has lots of manual external dials to control camera settings. The last difference is of course price. The X1D body currently lists for $8995 US or $12995 with 45mm lens, but the GFX 50s is rumoured to be $6995 for the body and with the 63mm lens $8682. I think this camera would appeal to those using high-end full frame DSLRs, that think medium-format is too expensive to invest in.
The GFX 50S body price is similar to the Nikon D5 priced and $6496.95 (with a 50mm lens $8100) or the EOS 1DX at $6299 (with a 50mm lens $7650). But more important Fujifilm's GFX 50s delivers a camera closer in size to Nikon's D810 than the larger D5.

Nikon D810 Beside Fujifilm GFX 50S Image Courtesy of DPReview

So the D5 owner could transition into the GFX at about the same cost of upgrading when Nikon comes out with their next upgrade in this camera class, and be using lenses that are likely of higher quality than those Nikon is now manufacturing. All in a package that is smaller than their current camera.
Noise Comparison to Full Frame
How different is the noise level on these two cameras compared to full frame Nurthrop Photography has indicated that there that the following has been their experience:
D810               X1D
ISO 60      =    ISO 100
ISO 625    =    ISO 400
ISO 2500  =    ISO 1600
Pixel Pitch and Image Quality

One issue that may give Nikon D5 shooters pause is the difference in pixel pitch between this camera and both the Fujifilm and Hasselblad cameras. The D5 has a pixel pitch of 6.45μm and the GFX has a pixel pitch of 5.3μm, which means the light measurement will be slightly more accurate on the D5. In my opinion, the difference in pixel pitch is not significant enough to outweigh the significant gain in sensor resolution.
A second consideration is edge to edge lens sharpness. My personal experience in shooting with Nikon full frame professional lenses and the high-end APSC Fujifilm lenses is the latter are sharper edge-to-edge at non-optimal f-stops, and I would assume that the same would be true of the yet untested Fujifilm medium format lenses.

The Fujifilm Advantage
Fujifilm Lens Advantage

One of the advantages of the Fujifilm system is their lenses do not have leaf shutters built into them, something that significantly increases the cost of a lens. This means very high-quality lenses can be crafted at a more affordable price. This choice brings their medium format lenses into a price range similar to that of full-frame DSLR lenses and combined with the higher resolutions perhaps a better quality image. Despite this, a leaf shutter lens from Hasselblad, using an adapter, can be used on the GFX 50S, in this way the camera permits both kinds of lenses to be used. The GFX 50S lens stable is within the range of full frame photographers while still allowing a leaf shutter option.

I think it unlikely once a photographer has shot with Fujifilm's lenses and experienced their quality that they would use other lenses on the camera. Given that the glass in both Hasselblad and Fujifilm lenses come from the same Fujifilm factory unless there has been a recent change, lens quality should be almost the same. 

Using a Non-Fujifilm Lens Does it Really Work

Having indicated you can use non-Fujifilm lenses in the field it might not be as exciting as it sounds. A good friend outlined his experience in using adaptors on his A7RII in the following way:

My experience with lens adapters for my Sony A7rII has left me somewhat ambivalent about the concept. True - it does allow me to use my legacy Leica and Nikon lenses on the Sony, but at a cost. The Voigtlander and Metabones adapters that I purchased lack electronic connections to the camera body and thus I lose all EXIF data related to lens and lens settings, which is a huge drag. I also need to own a separate adapter for each lens to make the solution practical, as changing lenses when I also need to switch an adapter from one lens to another in the field is simply too cumbersome. I have two Leica lenses that share a single Voigtlander adapter, and the worst case for me is when I am changing from an un-adapted native lens to the Leica lens that does not have the adapter currently mounted.  In this situation, I find myself juggling 3 lenses, the adapter, 3 front lens caps, and 2 rear caps - all while trying to keep dust away from my exposed sensor. If each legacy lens has its own adapter - it becomes a straightforward lens change - but sharing adapters just doesn't work for me. Way too much hassle - especially when I also lose EXIF in the deal. 
I would guess similar problems would exist with the GFX 50S.

The Advantage of the Hasselblad
What would I buy if I had the money, as the X1D and its lenses are considerably more expensive than the GFX 50S? I think the X1D. Given the advancements in camera accuracy in the field photographers are running in semi auto or auto much more frequently. So the wonderful manual dials found on the GFX 50S are perhaps less important, especially if you want a more compact field camera. This is a strategy that Sony Alpha camera series has adopted with some success, with the result that the cameras are the smallest and lightest in the mirrorless class of cameras. If you look at the comparison below the medium format X1D is almost the same size as the full frame A7RII, which is a stunning acheivement.



In addition to the smaller size, the X1D the camera is also more ergonomically friendly as a result of this size and its design. It also has a leaf shutter system in its lenses, with all the advantages that that creates.


Alpha Phase One
There is one more mirrorless camera made by Alpha that can take a Phase One digital back a much larger sensor that the other two mirrorless cameras. However, it is quite an unusual camera and costs $56,000. So it is not really playing in the same ballpark.

Articles Referenced

• Fujifilm GFX :: The Exact Fujifilm GFX 50s vs Hasselblad X1D and Pentax 645Z Size Comparison + GFX Price in Yen Leaked
• The Giants’ Battle: Fujifilm GFX Vs. Hasselblad X1D – Where the X1D beats the GFX and Vice Versa (Size Comparison Included)
• Japanese pricing of upcoming Fuji cameras and lenses (GFX 50S, X100F, X-T20), GFX accessories
• 15 Jan Pricing Info of Upcoming Fujifilm Products (GFX 50S, X100F, X-T20)
• UPDATED - Photokina 2016: Hands-on with Fujifilm GFX 50S
• Why Leaf Shutter Lenses Aren't Important for the Fujifilm GFX 50S
• Hasselblad X1D 50c vs Fujifilm GFX 50S
• Hasselblad X1D: 50 Megapixels, Medium Format, $9K
• Phase One A-Series Uses an Alpa Body to Make a "Mirrorless" Medium Format Camera
• $56K 100MP Alpa Phase One Shoot Fail