I got this headset for use with Skype, and it worked pretty well with the program apart from the mute button, which would go on and not come off with Skype 2. Works fine with Skype 3, and the audio is pretty good for VOIP usage.
The microphone seems fairly sensitive and intelligibility for the other end was better than any other headset I tried, and it was easy to get enough level on the mic.
As a pair of headphones the quality was good for speech and serviceable for music. Pretty much everything was right about this, apart from one major issue. The headband is made of fairly stiff plastic and is a tight U shape, which in its normal state keeps the earpieces a couple of inches apart. Into this you are meant to stick your head, and as a result the sideways pressure is pretty heavy. This is not a comfortable headset for long-term usage - at least for me it wasn't!