Still on AT&T, but unlocked it because 1. It's nice to have that option, especially since I'll be traveling to other countries soon, and 2. it's cheap to unlock right now, so might as well do it now in case the people capable of factory unlocking get shut down for whatever reason. Not to mention when the time comes, it'll be easier to sell an unlocked iPhone than a locked one.
It's also the principle of the thing. AT&T imposes a hefty termination fee for breaking the contract. That should be enough to make them whole, and all they should be allowed to get out of it. They shouldn't get to have their cake and eat mine too by both collecting an ETF *and* still keeping exclusive rights to the hardware.