Does P2 not have in game voice? I'm sure I read something about the audio voice comms stuff in source games having some improvements done to it recently.
Portal 2 does have in game chat, and it f**ks me right off. It's good quality, but doesn't work (obviously) during loading screens. "Fine!", I think, "I'll use TS instead!". No go. For some stupid reason, the Source engine decides to F**K the TS mic volume, FOR NO REASON. So much so that the volume on my mic goes so no one else can hear me. Same for the person I was playing with too.
The ingame is fine to use, but it gets very annoying when you realise you can't talk to the other person during the loading screen...
Oh, and turning the in game voice to "off" still meant the Source Engine f**ked with my TS mic volume. GOOD GOING VALVE.
Interestingly, this is my ONLY complaint of P2 so far.