I finally left AT&T Wireless. Their service has literally not worked in my house or most of San Francisco for years. The iPhone would display 0–2 bars but over half the time calls and SMS would not go through. And pretty much anywhere I was in the US, calls would drop at random intervals. Web pages wouldn't load reliably, either. It's not just me: AT&T has a nearly 5% dropped call rate, 2–3x worse than the competition. And it's way worse in dense areas like San Francisco or New York.
I finally switched to Verizon after several friends said their iPhones worked better in San Francisco. So far so good. I show 2–3 bars. I can reliably make calls from my house, I can load data over the 3G network, SMS seems to work. A cell phone that can make calls! I just wish I'd taken the leap earlier.
Ookla's speedtest.net app tells me Verizon gives me about 400kbps up and down for data at home. I've seen it go as high as 1500/800 and as low as 200/100 when I have better signal. More importantly the speed test has worked every single time I've run it. I can't even report AT&T speeds because the majority of the time, the test won't complete. Verizon voice quality also seems OK. Definitely has that talking-underwater quality when the signal is bad, but it's intelligible and, more importantly, doesn't drop.
I don't understand how in 2012 AT&T's network is still so bad. San Francisco is an especially challenging environment but you'd think after years of the iPhone monopoly they'd have found a solution. Or at least owned up to the problem. Also confused as to why AT&T's 3G reliability is so bad: my experience was the link would either be great or dead, no graceful degradation.
AT&T's goodbye to me after being a customer for eight+ years was to refuse to unlock my old iPhone 3GS and to refuse to refund a prorated amount for the last month. "Our corporate policy", they said, along with their policy of not providing a working service. Verizon's policy is to unlock after six months. Why did I stick with AT&T so long? Even my first experience with them was terrible. Stockholm syndrome, I guess.