I have been an AT&T customer since the original iphone. I can't say that I love them. T-Mobile new moves has me considering them. I wouldn't mind hearing other people's experiences regarding this. I definitely want simultaneous voice and data, tethering would be nice, (i know this is extra on AT&T, don't know if it's as easy with T-Mobile as it is with Verizon). I don't know how T-Mobile's LTE is though. I do have the grandfathered unlimited data with AT&T and corporate discount. I do have a Verizon iPad mini because of tethering, I would like to switch to a single plan for both at some point.