I've been with T-Mobile for almost 3 years and they have been excellent in every way. They offer the best price, best service and best customer care.
I am a former Sprint cutomer and even if Sprint made the switch from their incredibly limited CMDA service to GSM, I wouldn't got back
I can feel the backlash already of Sprint customers ready to jump on me for saying that CMDA is limited. The big limitations I am referring to are their crappy phone selection and no SIM. I sometimes switch my phones hourly, so CMDA is too limiting in that sense.
Larry B.