I was on AT&T with the iPhone 3GS and then was so pumped when I heard Verizon was finally getting the iPhone. As soon as my contract was up we switched back to Verizon thinking that if AT&T were as good as it was, Verizon would be 10x better. Wrong! As far as # of bars, I don't really know, but they both seem the same to me. To me AT&T picks up better in metal buildings. Verizon is a very temperamental service when it comes to where exactly you're at. But in terms of Internet speeds, AT&T KILLS Verizon! On my iPhone 4, I don't even bother watching YouTube videos because you have to wait about 3-5 minutes to give it time to load enough that you won't have to pause. We also just got LTE here with Verizon a few months back and we did some tests between Verizon's LTE on a friends phone vs AT&T's basic 4G on my boss's phone, both tests being on the iPhone 5. With maxed out bars on Verizon's LTE, the fasted speed through the speed test app that we could ever get is 9-10 mbps. Same test on AT&T's basic 4G network in the same place, which only had 2-3 bars of service, and we got a consistent 5-7 mbps. We were in Clemson last week for a golf tournament and I did a speed test on my boss's phone there since they have LTE on AT&T up there and I got 38 mbps with 3-4 bars of service. Verizon may have slightly more coverage area, but to me their Internet speeds have always been worthless.