It's an excellent book. It's meant for advanced players but intermediate players can definitely gain something from it. The diagrams are very challenging.
I really liked the book, imo one of the best book out there. His diagrams are good and the topics about advance fundamentals and mental skills are the best.
Highly recommended, along with the first volume. His work is among the best, he elaborates on fundamentals to the very minute detail and presents it in a very readable fashion with many real-world analogies and examples.