I've had mine for a couple months now, and logged enough hours of use to allow for "getting used to" the feel of the APM. I have to say this: they're really heavy and once I hit about 3 hours of use I'm quite relieved to get them off my ears. For the length of a movie or a long phone call, fine -- but any time I've tried anything approaching all-day usage I'm really feeling that clamping force on my ears.
The noise cancellation is fantastic, but when I don't need it I'm back to reaching for my open-backed Grado GW100 which weigh less than half as much and have very comparable sound quality.
Bottom line for me is that if Apple ever got around to selling a "sport" version of the APM with a bit less weight I'd sell these and jump on it, even if meant a step down from the premium (heavy) materials it's made with.