The latest round of testing (not JD Powers but cant remember the company name) they have a higher call retention rate than any other, but ATT has an easier time attaining signal. Thats why Verzion went from saying America's Largest to Americas Most reliable, and ATT says largest
I personally take all marketing superlatives with a truck full of salt. Marketing departments can twist any test or poll results into some form of "We are the best at [blank]." I rely more on feedback from real people.
I never listen to what anyone markets themselves as...I use to live on the Cape (Cape Cod) and every restaurant you went into had the #1 Clam Chowder...I asked one time the waiter of one of the restuarants who gave them that ranking...he said it was self proclaimed
Only you can pick the best carrier for the area you use your phone in. T-Mo is surposed to be hot, also and yet I got VERY poor reception where it said I would get excellent.
For me ATT wins hands down and I do a bit of traveling. This may not be so in your market. Remember that the cheapest carrier may not offer the best coverage.
I think it is self proclaimed, however I know that Verizon has spent a ton of money investing in their network. As a Verizon subscriber, I have lived all over the western US, and Verizon has had the most reliable service for me. However, your usage may vary.
Meh, I could care less. It's marketing as others have said. What does Sprint's "Most powerful network" mean? What does at&t's "You world delivered" mean? Nothing except to their marketing departments...