This book is divided in three sections:
1-A "fast-paced introduction to ASP.NET" (ch.1-11, p.1-228)
2-A "detailed reference to most frequently used ASP.NET classes" (ch.12-20)and,
3-A "Quick reference" of the ASP-related namespaces(ch.21-38)

My comments:
1-The fast-paced intro reads rather like a list than an actual intro. I mean you don't really get the picture of what .NET, or the elements described here, is about. And, though it certainly aims at programmers with previous experience, its code examples are not focused on the topic discussed but wastes pages upon pages by showing context code as well(which could have been clearly implied). So if you know the things covered here, it's a waste, if you don't know them you are not going to get any useable info. Finally occupying roughly the 1/3 of the book it could really get off the way.

2-The reference of the most used classes is nothing you couldn't find in the framework's documendation. Yes, it's focused on web-related classes and more handy maybe than the on-line reference but that's not a big deal. The big deal is, though, that it does not give you a better insight into the programming logic they supply. So what's the benefit?

3-The quick namespace reference part is the best one(compared to others). It has a UML formatted diagram of each namespace followed by a short description of its classes each with a list of its methods and properties. The diagrams are good and give you a panoramic view but an index of the UML notation is missing. Also the methods and properties of the classes are just listed and not described so what's the use if you need additional reference resources? It would have been better if this part were more detailed and covered the whole book. This would make it a real reference.

Overall, I found the book confused about its target reader, mixing too much with too little, certainly unbalanced, and the explanations a bit "wooden" and messy,lucking crispness and in the bottom line it is not a book you could use as complete reference by itself.