http://www.youtube.com/watch?v=vuebS4bTlGQ&feature=feedf
akaTRENT's review of the PC360, which pretty much mirrors everything I have said.
Okay, I didn't quote, but here are my replies:
LukaTCE, my recommendation if you can afford it is Sennheiser PC360 with Astro Mixamp. The Mixamp can be plugged into your PC as well. If you ABSOLUTELY need a soundcard, I'd recommend something with Dolby Headphone like the Asus Essence STX. I don't play on PC, so I can't really help you there, though if you got the Mixamp, it would render your soundcard moot anyways. If you DON'T need a mic or will mod a mic to a headphone, the Sennheiser HD598 is AWESOME, and even better than the PC360.
I personally feel that the overall sound presentation of the Sennheiser PC360 is BETTER than the AD700. The AD700 has a bigger soundstage and is a little clearer, but is also lacking in bass. The PC360 is better balanced. It isn't missing anything. It ain't bassy, but the bass is noticeably more present. Imaging/positioning is pretty much on par with the AD700. IF the modded 555 or 595 truly is what the PC360 sounds like, then I'd recommend them over the AD700 simply because they are more well rounded. That's only IF. The AD700 is still an FPS beast, but the lack of bass makes them more of a one trick pony. However, if you're getting one headphone for FPS, and one for everything else, then the AD700 is the best for FPS, IMHO.
halehaler, I modded a labtec LVA-7330 onto my Creative Aurvana Live. There is enough cup space to add a mic. They will work extremely well.
Xpresser, I haven't tried the A700 (which is actually NOT a closed equivalent of the AD700, but more of a closed AD500). The A900 is more like a closed AD700 from what I've been told from owners. They are COMPLETELY different series in Audio Technica, and people need to stop comparing them as simply open vs closed.
Closed headphones can offer spectacular and accurate positioning (i.e. DT770, D7000, Creative Aurvana Live), but the soundstage just won't be as big, which may make the depth of directional cues sound too close at times. Considering the A700 is known to have a large soundstage for a closed headphone, I'm willing to bet that they'll be fine for gaming, though not on par with the AD700.