Well, I have read basically every book out there on this stuff; Zatsiorski, Medvedev, Bompa, Siff, Verkhoshanki, etc.
Here's my take:
Supertraining is the most comprehensive but also probably the toughest to read. It takes siff an entire chapter to say what Zatsiorski might say in 2 pages.
However, Supertraining is based entirely on the principles of Science and Practice by Zatsiorski. (which is great, but doesn't cover as much as Supertraining).
Zatsiorski says everything Medvedev said (wasn't really impressed with Medvedev, although he is supposed to be one hell of a coach.)
Bompa is a different story. Periodization and Serious Strenght Training are good - but not necessarily powerlifting oreinted. Very good for understanding Periodization, Recovery Methods, and his EMG studies on different exercises are helpful.
AnimalMass