Ogg Vorbis is a fully open, general-purpose compressed audio format for mid to high quality...
Ogg Vorbis is a fully open, general-purpose compressed audio format for mid to high quality (8kHz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to 128 kbps/channel. This places Vorbis in the same competitive class as audio representations such as MPEG-4 (AAC), and similar to, but higher performance than MPEG-1/2 audio layer 3, MPEG-4 audio (TwinVQ), WMA and PAC. More Info »
When it comes to the proportions of the size and quality, Vorbis undoubtedly beat all the sh*t out of any mp3.
The process of encoding is slower than Lame's, but it's definitely worth it.