The music on this set is truly excellent, and for the most part the remastered sound is a noticeable improvement over previous CD releases of this material. The many alternative takes make for very interesting comparative listening, and quite a few of them are as good as or even better than the respective master takes (often Parker's solo is more interesting on one of the alternative takes, while the master offers a more polished performance by the band as a whole). If judging the music alone, I would certainly give the set five stars.
Unfortunately, there are some problems with the way Savoy has presented this music. The discs are packaged in cardboard sleeves attached to a spiral binder, and the sleeves are so tight that it is very difficult to remove the discs from them. To avoid scratching the discs, it would be best to take them out of the binder and store them in plastic jewel cases. Additionally, in the accompanying booklet, the track information is incorrect for a number of tracks on discs seven and eight. As of this writing, you can get a corrected track listing by contacting Savoy at inquiries@savoyjazz.com.
A more serious problem is that at least some copies of the set are still being sold with a defective version of disc four, on which most of the tracks are recorded about 10% too fast. If you already have the set, you can determine whether your copy of disc four is defective by checking the timing of the master take of "Donna Lee" (track 13): if the timing is 2:35, you have the pitch-corrected disc, but if it is 2:22, you have the defective disc and need to get a replacement. As of this writing, you can do that by contacting Savoy at inquiries@savoyjazz.com; after asking you a question to verify that you have the defective disc, they will send you a replacement. (At least one other Amazon reviewer reports that Savoy ignored his requests for a replacement disc, but I did not encounter this problem when I contacted them after purchasing the set in February 2004).
Those who don't want to spend quite so much money, or who don't want to go to quite so much trouble to correct Savoy's mistakes, should consider purchasing the three-disc "Complete Savoy & Dial Master Takes" (ASIN B00006H6A6). Though far less comprehensive than the "Complete Studio Sessions," it's a great value and provides an excellent overview of some of Parker's best recordings.