I've decided I'm going with EE, obviously I won't be getting it on launch day.
I'm aware EE phones are locked, is there a charge to unlock it? (eg Vodafone unlock contract phones for free after 12 months)
I may be wrong but i think it's £13-£15 to get it unlocked, though sometimes they will waive the fee. Please correct me if i'm wrong - not able to look for the info. Check the EE community boards, i think there's a thread on it there.