Wanna know how good the GFX and X1D image quality will be? Just look at those 645Z files and review!

You want to know what kind of image quality you will get on the new Fuji GFX? Just take a look at the Pentax 645Z reviews as it uses the same Sony 50MP sensor:

Review at PetaPixel:

The depth of field is beautiful. On smaller sensor systems the DoF drops off near instantly when using fast aperture tele lenses. On medium format you just get this beautiful roll off to the out of focus regions.

Ming Thein writes:

Does it have that ‘medium format look’? Well, given that such a thing is a property of both the angle of view, real focal length and aperture as much as the technical qualities of the recording medium, I’d say yes and no: it looks different from FF35, but not like full frame 645 (the CFV-39 has a 1.1x crop factor to 645). Remember, the sensor is 33x44mm after all.

Photographylife writes:

the Nikon D810 does look much worse compared to the Pentax 645Z at ISO 1600. In summary, the ISO performance between a medium format sensor and a full-frame sensor is obviously pretty pronounced and for a good reason – the larger sensor size does make a difference…

Studio Shot comparison at Dpreview:

And two more video review bt TCSTV and Matt Granger: