I agree with other reviewers who say they wish this book included more amigurumi patterns, but I don't consider that a major flaw; the ones that are provided make great taking-off points for adapting.
For me, what makes this book great is all the charts. I have a really hard time visualizing a project from written instructions. I have to read through written instructions slowly and really concentrate to get an idea of what the project entails. With charts, I can tell at a quick glance what different stitches are used, and get a good idea of the difficulty level. Charts are not so essential for projects using only single crochet, but for doing things involving single, double and triple crochet, like flowers, charts make the explanation so much clearer. It's too bad such charts don't seem to be very popular...
It's important to point out, for people like me who are drawn to crochet because of amigurumi and therefore may not have much experience with crochet, this book does assume that you already know how to crochet; it doesn't spend any time teaching you how to do the various stitches.