So you guys wanted a review of the HD800 using it on MW2, well. I just got the HD800 2 days ago and all I can say from my brief playing time, it's pretty much perfect for competitive gaming, the positional cues are pinpoint, the bass is not overpowering, when helicopters were online They didn't interfere with catching positional cues, I could pinpoint when people were over me, behind me, in the bushes, from miles away I could pinpoint if someone was sniping at me from up above and exactly which position he was at and on what floor he was. I couldn't do that with the Pro 900 and it wasn't as clear as with the HD800.
this is ofcourse using only stereo, I have yet to try it on Mixamp since I don't have it at the moment.
Comparing the HD800 to the Ultrasone 900 is really simple, the Ultrasone has much more emphasized bass, the explosions are brutal, the helicopters when they are on are interfering with catching the positional cues, almost impossible.
the soundstage on the Pro 900 is ridiculous compared to the HD800, to sum it up, the Ultrasone are more fun to me in terms of pure enjoyment considering all the massive explosions,gunshots and what not but the HD800 is for competitive and relaxing game, The hd800 in my opinion is almost perfect, and I adore the sound signature very much, really my cup of tea and I know it will get better!