First of all, in order to get started, I just want to say that while I love this headset and have never heard a headset that sounds as good as these, I've also not used a whole lot of headsets... so keep that in mind.
The headset came in some very nice packaging. The box has a flat finish on it, and looks very nice. It also has a lot of points to keep it locked, so there's no real chance of the plastic plate that holds the headset to fall out.
When I finished unpacking the headset, I immediately put it on, just to see how comfortable it was; that was, after all, a huge selling point for a lot of people, including me. I put it on, and wow, you can hardly feel that it's there. No ear aches, no nothing. I've worn it for 12 hours at a time just to see if my ears would ever start hurting, and they didn't.
So of course the first test after the comfort test was to listen to some music. I listened to a wide variety in order to check out how it performed. The first thing I loaded up was a song with a good bit of bass, because I'd heard so much about the awesome bass on this headset. I wasn't let down. The bass actually sounds better than my Logitech Z5500. Not as strong, no, but the sound quality is better. In fact, everything sounds better than the Z5500, not just the bass, but I really noticed how clear the bass was.
Next, I gave it a shot in my favorite game, and the game that made me buy this, Counter-Strike: Source. I play in CAL and CEVO (two leagues) competitively (albeit at a fairly low level), but still, I was being held back by my speakers. Not to mention my old mic was too quiet, so I had to pick it up and put it to my mouth to talk, which got me killed more than a few times. With this headset, I was able to easily hear people that I'd never heard before with my speakers. EVER. I could easily tell when people were coming up behind me (which is even better if you use the virtual 7.1 surround on the USB sound card, by the way), and I could tell if they were below me on a map... amazing
On the note of the USB sound card, it works great, however, I had one small complaint. Actually, it's not really a complaint about it, but rather, a complaint about my motherboard. When I use it and my USB keyboard and mouse are plugged in, the sound starts to crackle a little because of the USB bandwidth overload. Not the card's fault though, my motherboard is terrible for that, but I figured I'd throw it out there; if your motherboard has a bad USB bus (not sure if that's possible), don't bother with the sound card. Also, steelseries has a terrible download server for drivers, but the drivers that come with it are up to date, so no worries.
I really don't have much more to say, though, aside from the fact that you should buy it. It's a little expensive, but it's also very, very nice.