a few months back I moved to the Houston area... ATT coverage SUCKS around here... I don't get service at a number of places I spend time and was planning to move on to another service as soon as my time with ATT was done (can cancel with no ETF in another week or so)
with my job situation right now and my usage prepaid seemed to be a good option...
after some research I found that T-mobile has opened up the 1900mhz "ATT 3g band" in the area so I should be able to get 3g/hspa speeds on my inspire 4g and they had a package that should work perfectly for me 100min of voice unlimited txt and 5gig of "4g" for $30... I found a few friends with tmobile and they liked the service in the area... so i figured it was worth a try
I spent a little time online with att to get my phone sim unlocked, put in an order for a tmobile sim and waited
registered the sim and H+ showed up on the phone but was unable to get data... a little research and I ended up having to change the APN settings (found here Support: APN settings for data and picture messaging (MMS): Android
so far in the few hrs i've used it... I get a better signal and about 2x the data speed everywhere i've tried vs ATT
so in short... tmobile is a viable option assuming they have opened up the 1900mhz in your area... just spend the little time to make sure your handset settings are right and it should be good to roll