This is a hard book to describe. It isn't a how to manual in the terms of the actual low level implementation. It is more like a really good conference in a book, it gives you an overview of all the places you might need to go.
It definitely benefits from the author being a well regarded luminary of the field (at least from the maker side of things) not just from direct experience (though there are plenty of beneficial asides there), but in the reach of who they could get to talk about things for the case studies.
If you want to make an internet connected device I highly recommend this book. At least for now, surely it will go out of date in time, but given that much of it is so broad it will probably last better than one might think.