Being a big GC fan, I bought this book the second I saw it. However, after reading all of its 94 (not 64) pages, I was quite disappointed because I already knew everything that was in it.
This book is pretty much targeted towards the "new" fans, the ones who want to learn most of the basic four-one-one on the band. If you're a pre-"Lifestyles" fan, then you'll most likely already know everything they tell you in here.
Something else that irk-ed me throughout my reading was that the book, like most media on the band, mainly focused on Benji and Joel.
It's a lovely book, Dough Small obviously did his research, but my overall opinion is, if you don't know much about the band, go for it, if not, just get it for the few exclusive pictures.
Also, some of the information in the book is wrong. Unauthorized books are tacky, don't waste your money.