Very nice impressions! My impressions are the same with about 20 hours of burn in on the headphones and on my mind. They definitely sound different than many headphones. There's no sense of bass roll off, and the vocals are just so... hard to explain.
Anyway, my WS99 sounds more like a headphone with the common characteristics, but they excel at bassier genres.
Anyone has any tracks that sound great on the m500?
I listened to the whole of Dark Side Of The Moon last night, my favourite album and the one I am most familiar with in terms of sound etc.
The vocals were mesmerising, and like you said they are hard to explain, but it felt like I was in same room with them!
The main thing that stood for me was the drum sound. When I have listened to this album on other headphones in the past, whilst the drum sound is there and noticeable, it has not really made any impression one me (and don't subscribe to the theory it is either Nick Mason's drumming or the production of the album). However, with the M500s, they are really prominent along with all the other instruments, with natural, resonant sound.
In fact, I am finding that all instruments, including any overdubs, backing vocal (and flaws) are exposed with these headphones, the separation is absolutely fantastic without having a wide sound stage, it is all enclosed and very detailed.
Yes , I am really liking these headphones and so far I am impressed - I need more sound time with them as I have only had them a couple of days so the sound will get looser as time goes on.