The haptic feedback on the trackpad is amazing. I totally forget that it's not mechanical. I really dislike how big it is though. I know Apple tries to prevent false signals (e.g. palm touches when typing) with software but I just don't think it will ever work well enough to not be annoying.

It would take me a while to get used to having to press a button to show the trackpad like on the Yoga Book. I like that it automatically hides when typing, but constantly having to bring it back up, to scroll in a small textarea for example, would be annoying.

Merging the touchbar and trackpad, kind of like that Asus laptop that came out recently would be interesting. I thought it would be awkward at first but a lot of reviewers seem to think it's useful.