I just got myself a unlocked iPhone 6 model A1586 which apple advertises that could be used on both GSM and CDMA carriers like AT&T or Verizon as simple as changing the sim card on the phone. I currently use T-Mobile as my carrier of choice but I'm always open to switching. I sadly don't have anyone with either a Verizon or Sprint ( CDMA carriers are for me the big question...) sim card to try it out so I'm hoping someone here can say for certain that this would work. Thanks guys