The network. Don't get me wrong, I have no problem with AT&T. I've been using the carrier for about two years now and have had no problems. The thing that worries me is locking myself into non-LTE for 2 years. I live smack in the middle of Philly and NYC so I'm fairly sure LTE will be available in my area within the year.. so I'd be stuck on a non-LTE phone for a year, and that would kill me. This is the main reason I'm leaning towards switching to Verizon and getting the Thunderbolt. Anyone else feel the same?