Used a mate's BOSE-X headset the other week in a quiet aeroplane (turbine)and thought it was crap!
Must have been faulty or not switched on.
The Bose X is an excellent headset. I have four of them in the plane. Everybody who is a pilot and has flown with me is amazed how much better they are than theirs.
OTOH, the £300 Bose ANR headsets which are sold at Dixons etc for airline passenger wear seem to be a lot worse - based on my test of one of these. It got sent back.