Slightly on the plus side (compared to the examples you gave) it stores on average ~100 good quality mp3's on a CD-RW.

Well, assuming an average of about 200kbps (which is what my --alt-preset standard seems to come out to, or maybe a little more), a 700MB CD could hold 467minutes of music (assuming no filesystem overhead, but this is a little bogus anyway, so I'll ignore it), as opposed to, what, 80 minutes of CD music?

Alternately, I guess you could look at CD audio being about 1411kbps, right?