I'm really disliking that they don't work with a cable when turned off fully. I've never seen BT headsets have that limitation unless I'm missing something. But I know for sure my H7s work with just a cable. And so do my Parrots(although they sound hollow).
Right? The weirdest thing is that it was available on the P7W, so B&W should have the experience necessary to include that "feature" with the PX's.