We all just switched to AT&T and iPhone's about 2 hours ago. Still syncing everything.
It's a fantastic device. The 'deathgrip' isn't as annoying as I thought it would be. The screen, camera, everything blows my G1 out of the water. My first gen iPod touch was seriously lagging behind as well so this is a good upgrade, in the sense that it kills two birds with one stone.
AT&T were great - waived our activation fees plus paid for the ETF from T-Mobile. The service is alright. I get 5 bars of Edge where I live which is better than the 3 bars of GPRS (
:doh) to 2 bar of Edge to the occasional half bar of 3G with T-Mo.
Overall very happy with the iPhone. Looking forward to keeping it for the next two years.