This is a great review of the key facts for designing "solutions" that leverage AWS. I think I have touched most of the services mentioned here, but this book filled in my gaps. I'm not a big one for certification but AWS is so big, it was useful to have a map to the territory. Aside from a couple of obviously wrong answers in the sample questions, most of it seemed accurate. One thing: The Security chapter repeated information from the service-specific chapters: Since Security is such a deep concern throughout all of AWS, I almost wondered if that chapter could have been skipped.
I see a number of people have rated this 4 or fewer, but having read a lot of these types of books, this is a good one; and I also contributed a chapter to a similar book, and it's hard. So, naysayers, go write your own book.
Now let's see if I can pass the exam. :-)