I checked out the book at amazon.co.uk.
The problem for me, is the price. 28.50 British pounds, seems a rather too high price for a book containing 237 pages. There are also no reviews for this book, which can be a decision problem. I am sure, based on the look inside option, that the author spend a lot of time creating this masterpiece. For me the price is not so important, the content is.
I used the "Look inside" option and found out that the book is clearly written, with a lot of visuals which makes the topics easy to understand. The amount of pages contained in the "Look inside" option is very fair.
If you can afford the high price, this book is surely a very good buy. Tutorials are a great way to learn but mostly they lack indepth information, which is not the intention of a tutorial. I am sure this book is a very good in combination with using tutorials. Surely, this book will not let you down.
I did not know any books existed about Construct 2, so I am considering buying the paper version of this book.
My end conclusion : a worthwhile 28.50 pounds for a very informative book clearly written.
Edit : after I submitted this post I was checking amazon.de and found out that this book receives three "four" stars and one "five" star reviews. I read those reviews and they confirm my opinion above, this is an excellent work!!!