I'm no doubt bringing the level of discourse down a bit here as I have nothing relevant to say about sound quality right now (other than good enough). I picked up my set of APMs Monday at the Apple Store, and immediately went to the gym from there (were fine for working out other than flat on the back sort of things like crunches). First impression is that they didn't play loud enough. I'm not that guy, but for my usual random playlist composed primarily of 4,000 of my favorite songs of the 1960's and 70's, I left the volume all the way up and it was just barely adequate or too low. In several hours of testing, only a recording of Beethoven's 5th played loud enough to turn down the volume a notch.
I'm using iTunes exclusively (256 AAC), perhaps this is partly an iTunes quirk? There is some sort of loudness adjustment per song, but haven't been able to make it work. Perhaps some automatic feature has removed the ability to change manually as when I looked at the file settings, some had already changed from 0 db settings.
An hour ago, I received a set of AKG K361BT in the mail, and these play significantly louder. On the very few tracks I really do like to play loud (a couple of Fleetwood Mac tracks), they were loud enough.
I've not seen any comments here on how headphones do on absolute volume. Any feedback? I'm even wondering if I have a bad set of APMs.
Only thing I can add at the moment is fit. The 361's have shallower earcups and my ears touch. I'm assuming that will be uncomfortable for long sessions. I apparently also have a pointy head, and the APMs steel supports rest directly on my head. Slightly annoying and I will have to modify the headrest if I keep them. Controls are way better on the APMs as a by the way.