I happen to agree with both of the existing reviews so far.
This book is written in a concise and simple manner, so it's actually not as daunting as it may seem.
Truth is most live sound professionals (from my experience, at least) are not the most theoretical folks you can find. So a few diagrams, some illustrations, and possibly some examples from known brands (keeping in mind the spirit of impartiality that every technical book should have) would have definitely been a plus. Instead, the only pictures/illustrations you get are the ones on the cover (and back cover).
Also, I think some chapters were a bit superficial, as I found them more generally descriptive than explaining. The amplifier classes, for example. Now I know that Class A is less effective that B or D. But I still don't know what that really means, as there was no serious attempt (or lack of space) to explain the subjects with a bit more substance.
I think this book would be best suited as an aid to someone who's taking a Live Sound course, working on some job on the field or someone who has more concise and detailed books about electronics, amplifiers, mics, etc. Think of it as a text-book with some general knowledge that you can refer back many times.
To me, I would probably have liked it more if it had a couple less chapters, but with the remaining chapters a bit more detailed and explaining (with diagrams).