I found the book and its appendices to be extremely well written. I found the examples to be superbly written and extremely usable in my projects: there aren’t a lot of examples on basic things like selectors but there are a ton of great examples on much more advanced concepts. An additional feature that I found really helpful was the interactive lab exercises that begin around chapter two.
As a reference, which I don’t think was the primary intent, it would be difficult to use the book as some of the API is randomly spread throughout the book. The random spread does make the book a lot better though, because each chapter definitely builds well upon the previous chapter.
I completely recommend this book and can only imagine that the Second Edition improves upon the First Edition. I haven’t really found much negative about the book other than wishing the API wasn’t spread out so much, but the index is very good.