Pro: Clear, concise, and up-to-date coverage of a thorny topic. Focus on "Best Practices".
Con: Narrow in scope.
A number of chapters are devoted to building a web site for a fictional band called Jay Skript and the Domsters (you can see the final product here). I often find lengthy examples aren't useful, but in this case the site is generic enough to be easily adaptable to other purposes. Also the author breaks the example down in such a way that one can work through only parts of it and still learn quite a bit. All of the code is available for download from Friends of Ed.
Advanced readers will find this book useful as a "style guide" for writing better code. In particular the author shares unobtrusive ways to set up event handlers and to deal with browser compatibility issues. Client scripting is still very much an evolving field, and the author should be commended for his attempts to standardize some of the techniques. But those looking for a detailed reference on building complex