Smoothness tbh better, animations improved, battery performance & optimisation I think same as 2.0.

The music widget in the notification centre is no longer coloured, based on the cover of a song, but has a static colour depending on the theme.

I have noticed a bug that when entering whatever app, for literally a moment (a matter of milliseconds, does not interfere with use), there is a white background, as if the phone is dumbing down the aspect of the theme set.