I think for a lot of people, we get a provider, and stick with them, unless they suck bad, or just become too pricey. My first cell phone was on AT&T, when I had a very good state plan in Colorado. I kept it a long time. I don't even remember when I switched to Verizon, but I think it was when the Moto Razr came out. I needed a phone that was truly a Star Trek Communicator. With the New Every 2 deals, I have stayed locked into contracts ever since.
Verizon, like everyone else, has become pricey, but its network is rock solid, it has worked everywhere I have been -- even remote Mississippi (once I made sure I had roaming settings correct); and I can truly say I have had maybe 5 or 10 dropped calls in 5 years. And it gave me the Motorola Droid, and helped me escape from my poorly-thought out venture into Windows Mobile (the Samsung Omnia) when my beloved Treo seemed to no longer be up to snuff.
But do I have customer loyalty to Verizon? No. No love for, or hate for, Big Red. And thinking about it, Verizon provides a LOT of options. I have the ability to run on ANY OF THE operating systems: iOS, Android, Blackbery, Win Mobile. The downside: my phone is a brick outside of North America. The reliance on CDMA is a shortcoming, but ONLY if you are going to be outside of North America. For a week next year, it will be an issue, but up to this point, it has NEVER been an issue for me.
But if Verizon better than AT&T? I don't know. I haven't used AT&T in a long time. Is it better than Sprint? No idea.