I dumped ATT over a year ago and went with the lesser of the two evils for where I live for 4G, Verizon. I never regretted it. I can also say with personal experience certainty that ATT has a lot of incompetent people at the helm from engineering to program management.
Hi AT&T... Been a customer since 2007 and guess what, please stop spending money in other markets and fix the current sh*tty LTE network - I live in the US capital and LTE is fast, when it shows up... The alternative is Verizon which isn't as fast yet is always on... Sigh