I found the book to be well-written, insightful and entertaining.
BUT: My impression is that more than 50% of the presented studies and results have already been presented in Ariely's earlier books. Therefore, the book creates the impression (at least to me) that the decisions to write this book was driven more by the author's financial interests than by his will to inform his audience about fresh insights from his research.
This is an amazing book. It is not only very well written, interesting and entertaining, one also learns a lot about how people behave and why. Just for example: In one chapter I learned why I should make important decisions only when well rested and on a full stomach. In another chapter one learns that contributions influence people's decisions in favour of the contributors even if the people are aware that their decisions will not be made known to the contributors and even if the people themselves believe to be independent and objective (i.e. a very strong argument against political contributions).
I enjoyed reading the book. While it presented different experimental research on how people cheat but at the end of it, gives practical application. Its indeed a book that debunks the idea of rationalization. It's worth reading and everybody should read it!