I take it these are just for entertainment. You are not recording or mixing. Get the B&W.
But if you are looking for the best phones for the money I'd select either AKG K240 or their K271 depending on if you need the open or closed style. As you said you might like the noise cancelling feature then maybe the 271 would be the way to go. But if you have a quiet environment and can use open headphones the 240 are very likely the ones the recording engineer used to mix the music with and they sell for only $100.
One often overlooked issue when it comes to headphones is their physical comfort. If a pair doesn't feel good on your head it is going to be annoying to use no matter how good it sounds. I personally think the B&Ws are extremely comfortable. You can decide for yourself which you think sounds better but I would try them on for how they fit your head as well. Every head is different!
they are pretty good at noise canceling, when you turn it on it's like you turned the room volume level down some decibels. it's not completely silent, but pretty darn good. have yet to try it on a flight.
the sound quality is not the best. i use my IEMs or other headphones if i actually want sound quality.
another thing, QC15s need a AAA battery to work, no battery, no sound at all.