A very hard case keeps the cans in your carry expensive insurance, and Bose also includes an airplane adapter. The sealing pads noise well without any power, but unfortunately the headset does not work without batteries.
Noise cancellation immediately produces an environment virtually silent. QC15 blocks out a wide range of frequencies which the rest of the pack, what great just to reduce background noise without even playing any music.
Our test music sounded pleasantly warm and lively, with powerful bass and clear highs above. upper-middle can be a bit hard, which leads to smooth listening fatigue during long sessions of listening.
Although we like the general sound of the QC15, we prefer the Denon more accurate, and we wish it were possible to listen without power.