First of all, you are probably better to read the Toolshed FAQ about Tool if you want to learn more about the music. You can also find a huge collection of interviews there, where quotes may be better taken in their context rather than thrown in here and not referenced anywhere. Basically this book is a cut and paste of quotes from the members of Tool from various interviews throughout the years, and the author's "insights" are shallow at best. It was nice to read the quotes altogether, but if you have already read a lot of interviews, you know mostly what they are going to say.
The author is almost constantly setting up Tool in the context of "nu metal" (as in, how they are nothing like it), which is barely mentioned in the quotes by the actual band members. I found this extremely frustrating as it appears that this is the only other music the author knows of. Who cares? What a waste of paper.
While I liked the last portion of the book, where actually there haven't technically been any Tool activities, however all he talks about is Maynard and the other members' activities are not even mentioned. I understand that Maynard has the higher profile than Adam, Danny and Justin, but come on, it's about Tool, not Puscfier or A Perfect Circle. SOME mention would be nice.
Basically I liked reading the quotes and it reminded me how much I love Tool but if you really want to learn about the band, don't read this, just visit toolshed.down.net and explore yourself rather than read the author's inane lines in between the quotes.