I have both E90 M3 / F10 M5 and they're both awesome! (E92 m3 prior)
M5 is more luxury/daily. I like the soft close doors, heated/cooled seats, seat massage, night vision, a buncha features that arent' really needed but it's just cool to have. lol and the car isn't bad on gas for being 560hp. (but who buys an M to care?)
The only thing I don't like so far is where they put the cup holders. It blocks the controls.
Like someone said, the m3 is kinda boy racer. But I like it