I have no personal audio experiance, but what you are looking for in these forums are comments made by forum user Raven, who has made some monsterposts on the MP3 topic ( monsterposts are kind of his trademark )
If you are still worried about the mp3 files, I know that it is also possible to order the CD's with Project Meditation.
Bonus is that the CD-tracks last for an hour where the mp3 files last 40 minutes.
Hope it helps
