"If you’re leasing an iPhone, you’ll need to connect to AT&T, T-Mobile, or Verizon when you enroll."
Damn, this is the dealbreaker for me.
Leasing an unlocked iPhone and being able to use my current $25/mo MVNO of choice (US Mobile) may have actually tempted me (I currently buy outright and then tell myself I'll sell my current phone when I upgrade, but in reality I just have iPhone graveyard at home.)