I recently went through the process of getting a gaming headset and feel that I can offer an educated opinion on this matter. Ultimately, I ended up with the Sennheiser PC360 headset plus Astro mixamp 5.8. IMHO it's one of the best combinations available, albeit obviously at the upper end of the pricing bracket. I am very satisfied with the system, only being disappointed in one area: the PC360 cable is too long.
Let me explain though, I also bought the Astro Mixamp 5.8 because I wanted to be able to use my headset with my console. When I have my PC360 hooked up directly to my PC, the long cable is great. But when it's hooked up to my Mixamp, it is about 7 feet longer than it needs to be, and just creates a tripping hazard. I intend to mod my PC360s to allow for interchangeable cables of different lengths, so that I may have the optimal cord length in all situations.
Personally, the mixamp 5.8 is the best "wireless headset" solution out there, if you are interested in gaming console compatibility. It is a pretty high quality wireless transciever unit that you can use any headphones/headset with. The only other alternative I'd suggest is the Logitech G930s, which are PC-only but I have heard a number of people like them. They are nice since they are more "compact" than the PC360+mixamp.
I chose the PC360s because they have good sound quality (based on the same drivers as comparable Sennhsiser headphones), and also have excellent soundstage/imaging, which means they work very well with surround sound or surround sound processors like the mixamp, that use dolby headphone to simulate surround sound via headphones. The superior soundstage is critical since it allows better positioning of sounds in games, so if you play competitive FPS you can more easily hear where your enemies are, thus giving you an advantage, etc.
Before I bought the PC360s+Mixamp, I bought the Turtle Beach PX5/XP500s, which fulfilled a similar role, and a very convenient all-in-one package. However, I returned them because the build and sound quality was just not up to par with the price. There was audible hiss in the headphones as a result of the crappy amplifier, they rattled when you shook your head (loose plastic parts), and the sound quality was pretty mediocre. Although the PC360+mixamp route was even more expensive, the sound/build quality at least matches up with the price. There is zero hiss with this combo.
Anyhow, to summarize, IMHO the headphones that Astro makes are pretty subpar, and overpriced, just like all the other "big brand gaming headsets" out there (Turtle Beach, Tritton, SS, Razer, etc), they're all junk. However, the Astro mixamp when paired with a better headset is actually a very solid unit, and is a worthwhile purchase if you want wireless or console compatibility. If you are only interested in PC gaming, however, pick up a cheap sound card that does dolby headphone (such as the Asus Xonar series) which will do the same thing as the mixamp or tritton AX720 and get the PC360s, your money will be far better spent. When I use my PC360s with my PC, I use the Asus Xonar U3 USB sound card since I don't have any extra expansion slots in my PC. It cost $40 from amazon and produces the same result as any standalone DH surround processor.
Here is a
very worthwhile link to read. I highly suggest you look it over before making any decisions:
http://www.head-fi.org/t/534479/mad...hone-gaming-particularly-with-dolby-headphone