I was dissappointed with this one. I have and like his endgame book. This book seemed to me mostly fluff. His strategic suggestion is to use wishful thinking. The chapter titles are promising and even serve as a decent outline of material that someone of my level (fairly low) should study to improve their middle game, but the actual content isn't there. Example games are only useful if they are carefully explained. I can understand a point from a chapter title and even see that a game is a good example of such a theme, but without the proper explanation my actual ability isn't increased at all.
To be fair, I did check this out from the library at the same time as "My System" so it may have suffered from comparison, but for that reason I would suggest that anyone considering this book should simply get that volume, it will turn out to be a much better investment.