Sound Quality
The biggest problem I've seen with headphones designed to run passively off a wire, active with noise canceling, and wirelessly over Bluetooth is they tend to sound different in the various modes...and usually very poorly in one or the other...or both. The Phiaton Chord MS 530 suffers very little of this problem; it sounds pretty good and much the same in every mode. Not great, but quite good, all things considered.
In passive wired mode, the bass is well extended and tight though a tad high in level, making the MS 530 an warmish sounding headphone…