I really enjoyed this guide, and definitely found it useful.
I picked it up just as I was starting to go through my final 'spit & polish' draft, and it helped me catch a few little niggles that I might otherwise have overlooked.
I've seen a fair few reviews where people complain that a lot of the info here is common sense, or obvious; and if you read around the genre a lot that's probably true - but presumably that's why it's 'The Complete Idiot's Guide' and not 'The Lifelong Expert's Guide' :) And even if a lot of it might seem obvious, it's always good to have a handy reminder nearby. I don't know about you, but I found when writing a novel that there were so many things to remember all at once, that a quick and straightforward reference guide on my desk definitely wasn't something I was going to complain about.
I found it well-written, easy-to-read, and definitely of value.