I have used these for a few years and don't believe they were worth the money.
They seem to be high spec and professional standard but I don't see the difference between these and a pair worth about £30. The soundcard you get with it is a cool idea but not worthwhile. For me, it is annoying it fit it on my desk whilst using the headset. It is handy to be able to change the volume easily, but, a lot of keyboards have media controls and there is no difference. You can change between 7.1 and 2.0 if you wish, but why would you want to? When are you ever playing a game, listening to music, or watching a film and think to yourself "This would sound better in 2.0."? You can also change the volume of each 7 speakers individually, but again, why would you want to do this?
Another negative is power consumption which is very high and on my old Dell PC I couldn't use both mic and headphones as it consumed too much power from my USB port.
I will say however that they are comfortable and pretty good quality. The cable has got a strong woven casing and has lasted me a few years and still no difference. They are also super comfortable and feel like your ears are being hugged. The microphone seems good but it depends on what game you are playing and I have never heard somebody else using one so I don't know how clear it is. It does have a handy swivel on it so you can push it vertical if you want to take a swig of your drink or something.
Overall I think it is a decent headset but not worth the money. Comfortable, some good features, but also some features that could have been left out.