Moto x data compatibility

Sorry, I posted for the first time on using an ATT unlocked moto x in Des Moines, Iowa. The big issue is bandwidth as I am not sure if I am in a true LTE area or the HSPA+ areas.  Can you please help me quickly. I want to buy as my current Tmobile phone is wonky but I don't want buy something that will be stuck on 2g all the time.

Thanks