I have owned both.

In my last 2 residences, I had no problem with Verizon, and big problems with AT&T. In both locations, missed and dropped calls on the AT&T network were common. Additionally, I never see the 3G icon displaying on my iPhone in my home, and this morning I could not email 4 pics from my iPhone to my wife. They are still sitting in my out box.

I had a dropped call with a client earlier today. With Verizon, I rarely had any issues. I would pay 2x to have this phone be usable to me.

Verizon's plans and charges are almost dollar for dollar the exact same as AT&T, their global web/email services are actually a bit cheaper. Apple would have no interest in partnering with T-Mobile, heck, their service is worse and spottier than AT&T.

" Apple would have no interest in partnering with T-Mobile, heck, their service is worse and spottier than AT&T."

I've had the opposite experience. And T-mob customer support is far nicer.

In Raleigh, NC I had a lot of issues with T-mobile. The problem would be magnified any time I entered a building, on a variety of phones. Having switched to Verizon, I've only found two places in the area where I have poor service. (Too bad it's my research lab and my summer job...)

I had AT&T in Phoenix AZ, and then in Manasass VA, and when I moved back to Phoenix I gave T-mobile a shot. They had 21-day trial thing so I got a phone and drove all over the place, especially checking places I knew I would likely be, checking reception and such, and overall the quality beat AT&T.

It may be , though, that what works best depends on the particular region. Still happy with their customer support; they helped me in assorted ways and it was quite pleasant.