For those on the fence about buying the book, I recommend pulling the trigger on it. It moves along quickly, but I have really enjoyed it and the commentary from each band member. Each era of the band's career is talked about by each of the band members separately, and various guests. It gives you a variety of takes on many issues, but is written in such a way that it doesn't read choppy. It flows.
A couple of tiny editing errors no one will notice really (I've been a writer and editor for 20 years, so I pick up on it), but overall, its an excellent read, and a must purchase for King's X fans.