I was a bit underwhelmed by the book, especially given the praises it has received on various social media. The first part of the book contains a quick description of the main services of AWS ("the good parts") along with a few bits of wisdom from the authors' experiences using them (and potentially building some of them). I can't say I didn't like this part, but I had much higher expectations. Each service has a couple of pages dedicated to it, so each section essentially contains a high-level description of the service along with some commentary on limitations, trade-offs when compared with other services etc. Some things the authors describe probably do not exist in the public documentation and can be useful information for making a decision on which service to pick, but the rest felt like a very, very, very summarised version of the docs. For example, when talking about DynamoDB, the chapter describes it as a partitioned B-tree data structure and that's really it. No discussion about partition keys / sort keys / hot partitions etc... The second part is the practical and it's essentially a walk through of how to setup an application on AWS, starting from the basic parts (e.g. spinning up EC2 servers etc.) to a bit more advanced parts (network isolation / continuous integration etc.). This is probably something that would be useful to someone that hasn't built an application on the cloud before, but personally (having used some parts of AWS before) I just skimmed quickly through it and I realised there wasn't much to gain really. I managed to read the book in one sitting and it took me an hour or so.
In summary, the book feels like something that could be useful for someone who's making their first steps on the cloud and want to get a very quick & high-level overview of the available options on AWS and their pros & cons, but probably not extremely useful to people with at least some experience.