Reviewers label these the 'Bose killers' and with good reason - Sony have finally built a piece of kit with better noise cancelling than the QCs. And the sound quality blows them away.
So comfortable, great fit on the head, I can wear them all day. Noise cancelling is extraordinary - to the point where you take them off and are shocked by how noisy everything is. Don't take my word for it - read the reviews. WHATHIFI gave them the award for best headphones.