I was under the impression that Layer 3 produced a higher quality output for the same bit rate, at the expense of encoder complexity.
In my experience a 256 Kb/s MP3 is indistinguishable from a CD when played through good quality hi-fi equipment.
I would recommend trying (as I have done) playing a 128 Kb MP3, a 128Kb MP2, the ripped WAV and the CD track from Winamp so that you can compare and switch quickly between them.