Digital Lloyd has posted a short to the point video on his main site, "in a nutshell" differentiators between a GFX100S and 100II. You can find it on his main blog, thus no subscription is needed.
His points are well taken, and the video is worth watching if you are considering the 100II.
I have shot hundreds of images with the 100II, and agree that Fuji had plenty of time to write the book on Medium Format (cropped sensor cameras) but instead they appear to have just copied over the script from the 100S. Very little improvements if any. His point on AF accuracy is very true as the camera misses as much as hits. For me especially with longer glass.
I also have constant issues with IBIS with the 100II, where images have squiggles of blur throughout them, which makes the final file worthless. I have tried all shutter options, on a tripod with a remote release, and all have some of these IBIS issues.
The interface is identical to the older cameras, and I had hoped for a more modern look and feel. Q button is still way to easy to hit (at least for me) and there is no lock out that I know of.
Focus stacking also seems to have issues, although I have not tried it on the 100II as so far wind has always been a factor. However it seems that Fuji still can't be relied on to take the final image at sharp infinity and still requires a manual frame be taken.
I also am at a loss on the EVF, as I am coming from a Phase One IQ screen where a 100% view is very detailed and its very easy to manually focus. The 100II EVF to me is very similar to the 100's EVF (not the 100S) and viewing it at 100% is more a blur than anything else, same on image review.
ISO80 on the 100II and ISO100 on the GFX100 or S is also pretty much a wash, no real gains.
Hope that the camera will see some more firmware improvements to fix issues, but I can't see Fuji changing out the tired old interface.
Paul C