SPEEX’S FREENESS CANNOT BE DEFEATED. It may not be the best compared to some ridiculously complicated proprietary codecs, but it’s got a BSD-like license, so even Valve can use its open-source goodness in their closed-source garbage.
Also, I’m kind of disappointed that they took out the bandwidth setting that 1.6 had, you could crank the quality up even higher at the expense of a little bandwidth, which we certainly have.