It's difficult to write an objective review of this book, because Karpov and Korchnoi never got on in real life, so a lot of time is wasted by Karpov trying to Korchnoi in a bad light (the simple reason behind this is that Karpov was very much the Communist central committee's "poster boy" throughout the 1970s and early 1980s, and being a dutiful comrade, he did as he was told... Korchnoi on the other hand was not, eventually defecting to the west).
So - the book. It's a pretty interesting account of the matches leading up to, and the world championship match between Karpov and Korchnoi. At times it's very difficult to read - probably due to the transation of Russian to English - but offers a very good fly on the wall to the inner machinations of a world title match.
The coverage of the games is very good, with lots of readable discussion and comment by Karpov and his coach Baturinski throughout.
All we need now is a book by Korchnoi on the same event to get the other side of the story...