The book is a recap of the big blue Training Guide for the same Exam and by the same publisher and Author--which is also outstanding. However, this book is a later release so the items in the errata have been included in this book.

The differences:

The training guide has 95% of the material in this book (often with the same paragraphs, diagrams, samples, questions, etc. so don't buy both books like I did) plus additional practical examples, questions, and answers. For someone with less than a few years of experience with web development and less than 1 year with C# and ASP.NET, I suggest buying the training guide instead of this book. But for the more experienced and busy, this book might be just right. The sample code often only have relavent segments of a program which make the book a lot more compact. If you read sample code on other books, sometime you wonder if these people are trying to impress the readers too much with their 100 line program with only 10 lines of relavent information. Even MSDN is like that very often.

There's a few typo's I've found in this book, but that's it. No completely off the wall and difficult to spot errors I've found so far--I'm sure an errata section will be available soon for this book. I'm presuming the reason why his books are better is because the author runs his own Microsoft Certified Training Center.

I'd pick Kalani's books over Microsoft Press books any day. Books are cheap compared to other preparation material. So even if you already have a training guide for this exam or even if you already past the exams, I think his books will make great addition as a future reference and/or for supplimental exam preparation tool.