The BodyOpus book is outdated with sometimes wrong info due to Dan guessing about what to do. The book to get is Lyle McDonald's Guide to Ketogenic Dieting (or something like that). You might remember Lyle from his BodyOpus diaries that have been posted on the internet.
Anyways, BodyOpus is a good start, but if you continue with it, you will do yourself a favor and get the other book.
And yes the diet works, it is just a bitch to do. Willpower is key.