Tried out my QC2 in a Bose store before buying. I fly 4-5 hour lifts in a Chieftain doing aerial mapping and it beats a DC hands-down in comfort and noise reduction. I've tried the X and, while it is just a little quieter, it doesn't seem worth the extra $500 to me. I always carry a couple of spare batteries in my case (which is considerably smaller than the case for the X) The headset gives you plenty of warning before it gives up the ghost. It is also nice when you're traveling as a pax and don't want to listen to your seatmate tell you about their latest ailment or share pics of the grandkids.