This book was fine, but not great. I'm not sure exactly what I expected. I'm the kind of person who reads the manual pretty much cover-to-cover, and I found most of this book redundant with the manual, despite the author's protestations to the contrary. While the explanations in this book are more complete in that they provide more context than the manual does, I mostly just found them extremely verbose. For legitimately complex settings like flash sync speed, I didn't actually understand his explanations (and I'm not sure he did either). And while he claims to cover not just what various settings do but also when you'd use them, there were few useful suggestions for the things I was interested in (admittedly somewhat arcane stuff, like focus point selection modes).
I'm probably just the wrong audience. I also found the tone a bit off-putting. While talking about formatting, he says "if you're an efficiency nut," you might be interested in the two-button format feature. Maybe I *am* a nut for using a shortcut to format my cards (which I do every time I go out shooting), but it's an almost anti-intellectual tone -- in a book on a pretty sophisticated camera!
I did learn some new photographic techniques, like trap focus. His tips on shooting in general and making movies (like storyboarding) are pretty helpful (and not things you'd find in the manual). But there are other books for that stuff too.
To summarize, if you're comfortable with dense technical content and already understand a lot about photography and DSLR features, just read the manual. If you want a gentler walkthrough of the camera's features, this book makes a lot of sense. If you want to get better at taking pictures, pick up a book about less camera-specific topics, like Digital Exposure Handbook by Ross Hoddinot (which covers much more than just basic exposure).