The problem with picking up calls sound similar to the iphone 2g a friend of mine has. However, he did jailbreak his phone and I suspect that could be related. I don't know if you jailbreak yours but I haven't had a single issue with the phone with the exception of a half-second pause when I shutdown an app by pressing the Home button. But it doesn't happen all the time.

FYI, the maxis set I have already comes with firmware 2.2.1. I've installed various applications from Appstore, synching, used safari on 3G/WIFI, listened to music and podcasts and even watched movies on it. No hanging whatsoever. Never needed to reset the phone ever since I got it on 20th march.