I actually have been happy with 9.1. I just switched two weeks ago, and I used 8.6 all day every day. Now 9.1 all day. I am on Windows on one 42" inch 4k screen, (so no two monitors, so I can't speak on the whole shabotny that may come with that) and found it so much better to use all the time. I haven't opened 8.6 since. The two new snaps are end and midpoint. I admit to having snap issues myself, but haven't pinned them down. Since I can now toggle stuff like groups and edge picking with icons at the top I often find I've got one of these set how I don't want, so I have not nailed down a snap issue I could report, but I will probably be able to. It handles multiple projects open way better. Also 8.6 was crashing on me at least once a day accessing VRay materials, and these seems to have gone away. Inspector seems odd at first, but works great in practice. Scrolling the pallette dock is so priceless. The appearance is much cleaner, but like I said, on one big screen. I like that I can grab the edge of the formz window and pull it over, and see the desktop, or look at .pdf's.
Those light intensity sliders re not working for me with VRay plane lights though.
I thought of adding another handy toggle icon at the top of the screen for the one view you always want to go back to while you are working. I often find I gotta scroll to the views palette just to fish out the one view I always use. Maybe a home view icon that goes to the first view in the view list. I do use a tablet often and being able to peck a icon for everything in formz is working really well.
Just my 2 cents after two weeks. It has been noticeably smoother to use. A few things here and there and this can be a good solid version, maybe 9.2 is epitome formZ.