I was never going to be thrilled with this book because ugh, javascript.
But I was expecting more than a typical 2-star throwaway tech book. It was hard to get past the inconsistency (globals variables are bad, let's tack new methods onto global prototype objects!), bad editing, and repetition (I think one code snippet was repeated a total of 3 times).

A lot of people seem to like this book. If the idea of subsetting a language to produce a better variant is new to you, or if you've been stuck in the javascript salt mines, without noticing the river Lisp curving its way through them, or perhaps if protypical inheritance is a new concept for you, I can see how it could be a breath of fresh air. None of that holds for me, so it wasn't. The javascript subset he comes up with seems rather clumsy, and verbose, and easy to get wrong -- not very compelling.

Also, I disliked the railroad diagrams. In most cases a short English description would have been easier to understand, or a BNF would have been easier to read and equally precise. Many of the diagrams seemed gratuitous. They may read better on paper than on a screen. I read it in epub format, which also suffered from an unclosed italics tag messing up a chapter.

The parts I did like: The evidence of a keen mind on the other end of the book, and occasional flashes of insight. The clearest descripton of the "this" scoping mess that I've seen. Good descriptions of many of the stupid gotchas in the language, including the craziness that are javascript arrays.

If it had been called "Javascript: The Bad Parts (and a not very compelling attempt to work around them)" I'd probably feel like I got my money's worth.