I initially ordered the Black 256 7+ with a ship date of 9/19-9/26. On release day I went to the Apple Store and bought a 256gb black T-Mobile 7. I loved it and hesitantly cancelled my preorder. After a few days I missed the screen size and wanted to play with the dual camera. Last night I made a reservation for a black, Sprint 256gb 7+. I picked it up this morning at the Apple Store and popped in my T-Mobile SIM card before I powered it on. I paid it in full and it works perfectly on T-Mobile. I read that the Sprint/Verizon phones are unlocked and work on all major US networks. Not that I plan on moving to Sprint or Verizon anytime soon. Also, this version uses the Qualcomm chipset vs Intel. Not sure if this is a benefit or not. Bottom line: you can reserve your iPhone model under IUP at 12:01am and pick it up in the morning and pay in full. If you use IUP you will need to activate it on Sprint or Verizon. If you pay in full you can walk out with your unlocked phone and put whatever sim card you want in it. Just another option...