I use the phone in Los Angeles and San Francisco. LA coverage is better than SF coverage.
T-Mobiles coverage is very odd. I don't know if they tried to trick us, by putting up 3G towers in a city, but distributing the towers very sparcely, just so they could advertise that city as 3G or what. I'll be driving, I'll have 3G...then litterly a mile later, i'll go down to edge for miles, then i'll get 3g again for a mile or two, then back to edge for miles.
T-Mobiles 3G in Los angeles is sloppy, I don't think distrubiting your 3G towers sparcely counts as have a real 3G city.
Also there are lots of dead zones, in orange county also. The experience gets worse for me when I go to SF. My verizon friends in both cities always, and I mean always have coverage.