I have the book. While I haven't read it all yet, I have a few comments.
First off, I think it will be very valuable at helping to narrow the scope of what one should study. Looking at different lists of study materials, a person could easily end up with 5 or 6 large books, plus tons of web sites. The book narrows things down a bit. For instance, the GOF design
pattern book is hundreds of pages; this book has a concise 40 pages on patterns.
This book makes it clear that it alone is not enough to pass the exam. You will need to read and study other stuff also.
A coworker of mine who has passed
SCEA said the "Case Study" section would be helpful so you know what level of detail is appropriate for some of the diagrams.
My last comment is that I expected this book to be huge with a tiny font. It is pretty light with a large font. Again, it's more of a guide book than a single book that tells you everything, as the
SCJP books do.