I got mine. I'm not an audiophile, but the noise canceling is much better and the base sounds slightly less exaggerated.

The sales people couldn't articulate why or how much of an improvement I could expect. All they knew is that it has two microphones, one on each cup and improved isolation.

I tested by sitting next to a window air conditioner. With my old QC2, you can still hear it, but the sound was reduced. With the QC15, it totally cancels those sounds, like magic. I'll try it on an actual flight Monday morning.