Re: Pure Edition
I had problems with my Pure Edition on ATT.  It would frequently not receive calls while I was surfing the net, watching videos, etc.  I returned it and got an ATT branded version which works better.  It still misses calls from time to time, but not as consistently as the T-Mobile did.  When I called ATT to complain, they said they only "guarantee" ATT branded phones.  So far (a few months), my ATT phone hasn't been bad enough to complain.  I do think this has something to do with the cellular coverage at my home (which is also my office so I spend a lot of time there), and not just the phone, and I don't doubt that a PE works fine on many ATT locations.