Two things to keep in mind about this book; 1) it is ancient and 2) there were more than one sect of jewish Qabbalists running around at the time. This may not have some of the principle beliefs that most modern Qabbalists have via the Golden Dawn, but it is this growth that lets us learn about ourselves and the universe. Keep in mind that some corresponances may not be the same as the ones you have been studying, thus it is open for experimentation.
About the book itself...It is an astounding work that many early Qabbalists used as a reference before the Zohar became translated (only 35% of it). If you read and thought upon the things said on each page or section for one week, you may understand it, because it goes back and forth. What was not revealed before is later, so thus you must backtrack and make the connection yourself. This is a definite study book. You must STUDY this book to truly glean the maximum amount of knowledge from it.
This is not an easy read and it has no spells or magickal workings in it. It is a discussion between rabbi's about the Bible, Qabbalah, and other modes of Jewish thought and religion. This pertains mostly to the dogmatic Qabbalah that so many of us hear about, but really don't see or study.
It is well worth the money to buy this book if you are at all interested in the Qabbalah, the Bible, or Jewish teachings. It will reveal things for you if you have the patience and the tenacity.
Seek and ye shall find. <- It's not just an empty saying.
One of the best books to study dogmatic Qabbalah, and I would recommend this book to anyone who was a Magickal student, or someone who was merely interested in cultural religion. A MUST READ by all senses of the word. You are missing out on a lot of revealations if you don't buy this.