Ive never had any problems regarding comfort. Other headsets I've used always made me feel like there was a lot of pressure on my head, but this one does not. And the microphone is great. I don't use teamspeak, what I do sometimes is play games with my friends while talking with them on skype and my main friend immediately noticed that I had a new headset because of the quality of the sound.
Is is better than the Siberia V2? You be the judge, right now in Amazon the 780 is at $57 and the Siberia v2 is $90. In the reviews they bith have 4.3/5 which is really outstanding. I recommend you read some reviews and decide on your self which is better. Also go and see unboxings and reviews of both on youtube, that might help you make the decision.