O2's CS was outstanding though (and, unlike T-Mobile's, free), and they did lovely things like let me give 3 days notice instead of 30 when I stopped my contract - "oh, we'd never keep charging you once you'd moved your PAC" was music to my ears.
My experience as well.
Their coverage is poor and they can't really be bothered to roll out 3G at all, but I have to admit, some of the other carriers could learn a thing or two from their customer service. (Referring to their telephone support, not the retail stores: the retail drones are bloody hopeless)
Cancelling 3 was hell. 30 days notice is after you can even convince them to do that, after they've begged, pleaded and insisted that you get some crappy alternative to the iPhone with them. And after half an hour of arguing against that, that you give the contract to a family member. And then after half an hour of arguing against that, that you give the contract to a friend. Then a colleague. Then "OMG please, anybody, my job depends on it" (not in so many words). I ended up hanging up and writing a letter. If Apple went with 3, and there was no unlock ability (shady or not) then I'd get a Pre.
Thankfully the customer service of Apple and 3 are absolute polar opposites, so I can't see them choosing 3 in a million years