128kbps AAC files...

128 AAC (iTunes) is pretty good. 256 AAC is slightly better and hard to identify against redbook in A/B listening on music. Of course, both are lossy so this is not audiophile quality but it is pretty darn good - say 99% there.

It is great.....on an iPod. For an even moderately revealing home rig though, you should at least lossless.

Looking through archives for PC users I see now they have a Windows 9 format that seems to be like AAC.
Chazz

I just decided to stick with the AAC encoder on itunes. It's easy to use and I must say I'm pleased with the results.

About one tenth of the actual information from the CD is presented. Barely suitable for listening on ear buds.

192 is starting to get reasonable, but the cymbals and high end go warbly still. Forget about low end. If you intend to do serious archiving try at least 256 or for best results, FLAC.