hey rich did you ever get this set? and if you did how is it?
I've got that headset (Tiamat 7.1 Analog) and its great. You need a sound card that has analog outs, of course, since its not one of those toslink types. It actually has individual speakers instead of simulated surround like most (but not all) other 5.1 and 7.1 sets out there. It uses 4 tri-pole 1/8th inch jacks for all 8 channels, and another for the microphone, make sure your sound card can support this before buying (or replace your sound card as well).
It makes a huge difference in locating sounds. People will say they can locate sounds with stereo headsets with simulated surround, or built in surround effects from the game they're playing, but they'd locate them quicker and more naturally with these.
Downside: These are not good for music playback. I suppose if you've never heard anything better, you might not know what you're missing. But these are not good for people that want one set of headphones for everything, they are for gaming specifically. They do block outside noise quite well. I can have the TV blaring in the same room, and when I put the Tiamat 7.1s on, I can barely hear the TV at all. When I take them off, I'm shocked at how loud the TV was all that time.
I also have Sennheiser HD 555s (as it turned out,
not the last headset I ever bought) and the 555 is much superior for music, but much inferior for locating sounds in games. I have both sets hooked up to my PC and I switch outputs on my sound card to select one or the other. The Sennheiser I use for stereo audio, and especially music, the Tiamat 7.1 I use for games that support directional sound. Right tool for the job and all that. Anyone who believes any stereo headset is superior for games in general is mistaken.
One caveat... the microphone included with the Tiamat 7.1 sounds like crap. Lots of buzz. I stopped using it after a couple days and use the same Logitech USB desktop microphone (now discontinued, but still for sale on Ebay at somewhat inflated prices) I've had for years instead.