+ screen (I NEED THIS SCREEN FOR MY N800 )
+ keypad slider (having one)
- keypad slider (having d-pad moved onto it)
- kickstand (too small, no way that it can be used as hand-strap)

Size... well, IDK on that. I'm happy with N800 size. I might be happier with N810, or I might not.
Styling is way too subjective, but I think I like the N800 better. The most curvaceous tablet around, and the color scheme is nicer too.