I would actually rate this book 3.5. It's a decent enough book to keep your preparation more structured, focused and on track towards clearing the exam. Remember, it's easy to get lost in MSDN. There are a few obvious typos which are easily spotted. A few of the topics covered need to be supplemented with additional information in MSDN. And I think William Ryan is the worst author of them all.

I recently cleared this exam so in case you are still working on it (instead of 70-503) here's what I did:

- Read this book cover to cover.

- Finished most of the Hands-On-Lab excercises.

- Supplemented some of the topics namely:
Custom Soap Headers/Extensions, .NET Remoting (w/ MSDN Samples), WSE 3.0 (Custom Policy Assertions, WS-Security, SoapFilters, WS-Messaging etc) from MSDN and WSE 3.0 Documentation.

- Coverage of Serviced Components/Enterprise Services/MSMQ is adequate from the exam perspective, although I did lookup some of the classes in MSDN.

- Took practice tests directly from MeasureUp (Practice Test/Exam voucher combo). Did not use the practice test on the CD.

- Took me about a month to prepare. Though I have some prior experience of building distributed applications.

The actual exam duration is 125 mins. Total of 40 questions. Passing score of 700 out of 1000. I got a score of 953 and probably 2 questions wrong.

Hope it helps and best of luck!

Here's a response to the comment made by 'pturner75':
You can use BeginXXX and EndXXX methods to invoke web services asynchronously in .NET 2.0. Just generate your proxies using wsdl.exe or wsewsdl3.exe instead of relying on auto-generated VisualStudio proxies (via web-references).

Buy it used for no more than $10 (or don't buy at all), and only if you are preparing for exam. The book is terribly written, hard to read, labs hardly cover the material in chapters. It is VERY unprofessional.

I was cruising reasonably ok on the first few chapters and quite forgiving for the few typo and bugs on the sample codes. But somehow as I went deeper towards the later chapters on WSE 3.0 the errors become more pervasive that I lost my appetite. Now, I am not sure whether I should rely on the practice test to past the exam.

This book really is very bad. Lots of the code samples
will not compile in C#.

I originally gave this review two stars. But after reading
all of it, I gave it one. The worse author is Shannon Horn,
who asks easy questions and is very verbose. He repeats the
same questions asked in previous questions.

Also, the C# samples have lots of bugs, syntax errors, and a
lot will not compile. Not to mention that lots of
the explanations do not cover how to use the tools.

Sara Morgan dropped the ball on this one. Hopefully Microsoft
will hire the same authors from 70-526, and 70-528 for
the next Web Service exam.

Ok, it covers most of the topics.
But yikes, it repeats itself all the time instead of at least try to get a little depth. I wouldn't recommend it. Only if you are a real beginner.