In January Consumer Reports surveyed over 58,000 of its subscribers on the quality of their cell phone service, with categories for voice, data, customer service, and coverage.
Both overall and localized for 26 different US cities, Verizon far outperformed AT&T in this survey.
It's customary for the tech community to scoff at Consumer Reports' findings, and often with very good reason. But if you ask 58k people, mostly the sort of middle-class folks that are typical CR subscribers, how satisfied they are with their cell phone service, the results IMO can't be easily dismissed. In this large sample, far more people were very unhappy with AT&T than with Verizon.
I found this -- as a person buying an iPad 2 as
1. a netbook/iPad/GPS/e-reader replacement, who
2. neither owns nor wants a smartphone, and who
3. spends nearly 100% of his time in large American cities
--to be a compelling argument in favor of Verizon. Far more compelling than any anecdotal evidence, which is all I see in this thread.
After a month with my 64GB white 3g iPad, I've had no reason to regret my choice. Verizon has never failed to connect, never dropped a connection, never seemed particularly sluggish (although I wait for wifi to download large files), and their pricing seems to fit my usage patterns more economically than AT&T's would have.
My point: it's possible for a rational person to research and analyze this question and come up with Verizon as an answer, and then be happy with that choice. Contrary to some assertions otherwise.