Yeah, Skype uses too too much CPU, at least compared to similar programs. I don't think I could run anyting that uses noticeably more than Ventrilo as my CPU load is already really high when the Stream Encoder + BW + Vent are running.
We wanted to test stuff with mumble, but I don't think we found the time yet.

We also had other problems. Like Qualification Round 3 Day 1, I was stream obs and the sound of Artosis&Tasteless was really bad on stream (was fine on Ventrilo tho). We later found out my onboard sound chip was amplifying everything for no reason. Fixed it by pluggin in an old Soundblaster Live! I still had from years ago. Last weekend, when intrigue was doing stream with Artosis & Tasteless their commentary was sometimes delayed for several seconds, due to the bad connection they had that day