I purchased my Model 1661 phone through the Apple upgrade program. I originally purchased it as a Sprint phone. I was told by both a Verizon and Apple Support rep that I would be immediately be able to switch to Verizon since it was unlocked. I even confirmed in store it was unlocked. While I did have some issues switching (imei would not show up as unlocked) eventually a crafty Verizon rep got it to work and my phone works well. Save for the fact I don't have access to VOLTE. The Verizon reps have told me that even if the phone is unlocked, some features are only available on Verizon phones. And if I had gotten an unlocked Verizon phone it would work. That there would be "software pre installed" That makes zero sense to me. Needless to say this is important to me. I'm on my phone often when I need access to data and I don't have wifi. I have gone to an ATT Store and they put a sim chip in and it worked. My question would be two fold: Does the Verizon story have any merit? If I do switch to ATT I know it is compatible, but am I sacrificing network coverage and potentially limiting the available bands? Thanks!