Small differences noted so far :

* virtual memory maxes at 64MB instead of 128 (a pity, it could probably use the difference!)

* battery status bar icon doesn't show a popup when clicked

* file manager does not show the "bluetooth" branch with phones and other devices in it (the menu item File/Send does work though.

Restoring a backup from a N8x0 seems to work with no side effects, which is pretty neat.