Just wanted to let you guys know if you haven't tried already. The stock Droid Maxx works on AT&T with HSPA+ internet. Popped in my girlfriends nano sim from her iPhone 5 and switched to global mode in settings. Within a few seconds I had reception and it made and received calls. Ran a speedtest to ensure internet connectivity and had decent results. 3Mbps/2Mbps This was next to impossible on my old Droid Razr Maxx thanks to a locked radio firmware, even with root and custom firmware loaded. I have included screenshots. Be careful putting in another sim card into your phone and your sim in someone else's phone. If you bought your phone from a third party vendor that requires you to keep service active on the same phone number or you might pay a penalty.