Real leather!!!!!!!!!!!! I've compared the pads (even swapped out the slightly different foam on the inside) and I didn't notice much difference between the pads. I'm going to redo the test though as I have a set of Mk2 pads coming in from Japan.
The bass and the midrange are the two areas which I really dislike on the stock Mk2/A. The bass is overblown, with a midbass hump and limited extension while the midrange isn't as linear with a "honk" which exacerbates some tones. In basic terms the Mk2/A has lost the main quality of the Mk1, it had no sound of its own.