I had the good fortune of knowing the guy who eas ripping every star wars game from just before episode one till recentlt.
This meant i had acess to the raw rips, not the mp3 ones he upliaded for everyone else. I also studied every ounch of music from them to rebuild the score in the most complete fashion ever made. Not till GGCTuK came along did anyone try this again.
But as for quality, disc 1 and 2 of episode one are very good quality. Disc three is less, and disc four is a mosh of liverecordings and such.
Episode three is either clean lossless or dvd rip from the german dvd.
But youll find no better till its released.