If you do take the plunge when you're contract is up, it would be good to hear from you as to whether or not the other carriers treat you any better, and under what circumstances. I'm locked in for now... although I came close to changing to ATT. I've always been of the opinion that the top skill of any TeleCo. is a a keen sense of a) what the market will bear and b) just how tight they can set the screws and c) a keen willingness to screw you with telephone reps. only too happy to do so. eg. when I got my nexus the sales dude said I could keep unlimited since I was purchasing before midnight... but when I activated it a few days later, it dumped me to a phone rep and the dope tried to tell me she could not set that up that way because the software wouldn't let her do that... and tried to use the excuse: "well you only use 1/2 a gig anyway..." trying to make me swallow a 2GB limited plan just to get me to go away. But I had the order *printed out* and *in hand* and it said "unlimited". She said she'd call back in 72 hours after working it out with her supervisor or whatever. This is bull**** because if you pay full-fare for the phone they'll give you an unlimited plan. It took them 5 days but a rep DID finally call back from VZW telling me my unlimited was reinstated. But I'll bet that there is an asterisk on my account when I go back for another one down the road.
Suffice it to say I've not heard great things about ATT... but it seems mileage will vary greatly. I expect some folks have better service from one or the other... but I'll bet most of us have been screwed one way or anther by all of them. I suppose one advantage of the other guys is the GSM network but if you don't travel abroad, perhaps it's not a big advantage.
I'm not a huge fan of any of the carriers, but I expect if more folks were like you and actually put their money where their mouth is, then these TeleCo's might be more customer friendly... We just stay with these respective jerks because it's easier. That's one reason (I think) they all fear android and why they try so hard to subvert it with their restrictions and bloat because it *IS* easy to move from one carrier to another (so long as you stay with android) as the data transfer is easily done.... VZW backup assistant is actually on my Gnex... but wtf do I need it for? So VZW can make me think I need it when I switch phones?