Just played with a demo GFX for a few minutes while talking to the reps. Hot damn!

That thing is phenomenal. I'll never have the need nor the budget to grab one, but that thing pulls you in instantly. Everything feels sturdy and expensive (which is good), the lens is no bigger than a normal full-frame lens. The image quality - from what I could see on the back screen - is ridiculous. I was framing other clients in american frames and their individual eyelashes were tack sharp when I zoomed in enough that an eye filled the screen. The focus fall-off was butter smooth and much more enjoyable than on APS-C. Even at apertures like 5.6 you had ridiculously creamy backgrounds. This was on the 63 mm f/2.8 (which is equivalent to a 50 mm in FF).

BTW, the screen is as responsive as an iPhone, I did not expect that. The viewfinder is big and bright and the controls are all easily accessible. Overall, very enjoyable 10 minutes playing with that beast. 5/7.