well I think q3 doesn't support 5.1, we would of see it in settings, so it woouldnt matter. I got medusa 5.1 and it's really different when I set it to 5.1 ( on the audigy ZS 2 ) but still I think I hear better on 2.1 atleast louder and more clear ) . Anyways, you can always go to 5.1 if the maker's good quality which sennheizer IS, cause you'll be able to set it on 2.1 for most of your uses ( if you believe in 5.1 for some uses ).

sucks balls, u can try pioneer one i have is comfortable as hell, i can wear it like 48 hours per day, and no pain for head/ears

this one is quite neat one, what i wear now http://www.pioneer.eu/uk/products/42/67/226/SE-M290/index.html

25-30 euro, worth it

Still never failed me - (THESE) . Ok they do have there limitations in some situations

I'm also looking for some headphones atm to match my sound card. I was looking at the sennheiser HD555 untill i read about this:
http://forums.overclockers.co.uk/showthread.php?t=18154591
additionaly these do not have an inline volume control which is something i cant do without
so, i am now thinking about getting HD595 with a HZR62 Extension (http://www.hifiheadphones.co.uk/sennheiser-headphone-extension-cable-with-volume-control-05248-prodid-1860.html)
would this work?

to change the volume on the fly. i hate using the onscreen methods. this wont work, unless i use another adaptor for 6.3 to 3.5