CBR OR VBR?

Which is better for ripping music? Quality matters.

thereby attaining a COMPROMISE between quality and speed
No, dumbass, it has nothing to do with speed. It uses a lower bitrate in some places, so that it can use a higher bitrate in other places.

320kbps CBR is complete overkill; 224kbps CBR is usually more than enough, and a VBR file of the same quality will probably be at least a quarter smaller in size.