I have a set of Bose X and a new set of DC X11's and I like the X11's better.
For those who have never seen it, I had a set of Bose QuietComfort 2's headphones and saw on Ebay an adapter for them to make them work in an airplane! Too cool. They are called Iflymike. They hook onto the Bose Quiet Comfort 2's and make a nice set of ANR Bose headsets for half the price. I was thinking about selling those since I have the others now.