Bet me to it. I used to take all my iTunes tracks (I only downloaded the free ones since I'm a lossless guy and only buy CD's) and burn to (RW)CD then rip back to Apple Lossless thereby keeping the quality as is. It is when you re-rip (or covert lossy to lossy) to a lossy format that you compound the quality problem.
Everyone says this but it need not be true. I think people are just repeteing what others say without understanding it.
This is a two step process. Step one converts AAC at 128K bps to AIFF. This step losses exactly zero information as the AIFF format is lossless.
Step two converts the CD back to AAC or MP3 or "whatever". You have a lot of control here and you can determin if there is loss or not andhow much. For example if you converted to Apple Losses then there is ZERO loss from your AAC file but at the cost of a lot of disk space. But if you convert to (say) 256K bps AAC then there is still almost no loss over the 128K files you started with as the information thrown away durrign compression was never present in the 128K file.
basically you can control the amount of trade off between disk space and loss of quality. The quality loss wil range from zero to "a little".