My first impressions:
The truth is that I expected a lot from this headphones and they are not ultra-impressive compared to my Apple in-ear earphones. I find that they sound very clear but bass is lacking is some songs (and I am not a basshead). In other songs where I didn't expect bass, there is some and very good sonding. Also, I had read that these headphones were very confortable when using them with glasses, but personally I can't wear them for too long because (I don't know if it is because of my glasses) they start to annoy a little. Maybe with the time I'll get used to it, but I expected more after expending 160€ on these.
UPDATE: I have to admit that they have improved with the time. In my second day with them I feel that the 598 have a more noticiable bass and sound good with almost any kind of musical genre (specially acoustic and instrumental music), anyway, I found a little lack of bass compared to my in-ear Apple earphones. Regarding to the comfort, these headphones are very soft and confortable, the problem I have is more because of my glasses (they hurt when I wear them for long periods of time, even without headphones... :/). Summarizing: these headphones sound great with any kind of genre, but you may find that it lacks A FEW MORE of bass compared to other headphones in electronic music.