The book is pretty well organized, with most chapters presenting the development of a node application. I found the chapter on web sockets especially interesting - this is something long overdue in web applications, and node has excellent support for the feature.
The node runtime model is pretty interesting: a single-threaded event-driven model in which there are no blocking api calls. This avoids most of the problems of multi-threaded applications while still providing a high level of concurrency.
The book concludes with three chapters on database interfaces in node. And that brings up one of the few criticisms I have of the book: I had the sense that the publisher wants great big thick books, so having three separate chapters about three database was just the ticket.
But the size and format of the book was not the author’s fault, and the content was useful.
My major complaint is about the number of errors in the book, both in the text and in the printed code. Again: I blame the publisher for this. If you’re going to take 85% of the book’s revenues you really need to take some responsibility for copy editing and, sadly, this publisher simply failed.