I enjoyed this book a lot, and will be reading it a second time. It gives you an insight into an opening that the author, one of the greatest chess players of all time, clearly loves deeply. I particularly enjoyed reading how this opening developed over the years that Karpov was engaged in epic battles with Kasparov. The book also provides you with a bit of a behind the scenes of how the great players prepare for combat, with dedicated researchers and similar.
Before purchasing this book though, it is important to understand what it is, and what it is not. This book is not:
1. an English opening system (like Kolsten's "Dynamic English"),
2. an upto date theoretical tomb on the English
3. a guide as to what variations to play.
This book will be of interest to players, black or white, who want to:
1. gain better understanding of the types of positions and games that specific c4 lines lead too - e.g. 1. c4 e5, 2. Nc3...
2. gain insight into the hedgehog and other symmetrical lines (that can also arise from 1. Nf3)
3. are building a classical English defence against c4 (i.e. e5 or c5)
4. would like some understanding on how great players learn by imprinting critical games in their minds
5. enjoy reading a true great of the game describe classic battles
The chess lines in this book can transpose into d4 openings. I have come to the conclusion, that the reality is, that to play chess for "an advantage" in the opening, a price to be paid is that transpositions can occur. No 1 book can cover off the English and all these transpositions, unless one is willing to compromise with a set system (e.g. Kolsten's 2. g3). Set systems can work, but are not for everyone (they can ultimately get a bit dull, at least for me).
If you want to play English lines like the four knights, or too augment a d4 repertoire with some anti-nimzo lines or similar, this book is useful, but will need to be supplemented with a more theoretical book (I have Vladimir Bagirov's books - although I guess they are probably out of date).
So with that said - I really do love this book. If you like chess, for the sake of chess, and are not looking for someone to tell you what to play, but rather to read a Grandmaster describing what he played, and the struggle over English variations during his time at the top, all you will enjoy this book a lot.