iTunes-Lame is a must-have for ripping your CD library. I can certainly tell the difference in quality from a iTunes-ripped CD. I highly doubt that Apple uses its own consumer (iTunes) algorithm for ripping music to its iTunes music store. Why should you?

I've found that this version that supports multiple cores is much faster than the original. Compare them yourselves, I have two WAV's compressing simultaneously at 16x each (-V 0 --vbr-new -h) on my MBP.
http://stimuli.ca/ituneslame/

Incomparable MP3 converter!

You don't want mp3s, you want Apple Lossless

Mmmm.... Lame ain't an mp3 encoder. My favorite iTunes add on.

Not only does this work great, once I upgraded the built-in LAME encoder with a Universal Binary (available at http://www.rarewares.org/mp3.html) for my Intel Core Duo, it was really fast too.