Personally, it took me more than 6 months to finish this book from the moment when I saw it at the bookshelf at Malta airport until the moment when I was done with all its additions and appendexes. That's definitely my fault, not the book's as it's very pleasant to read unless you want to practice every single concepts that it's aiming to teach you.
That's not the first book on personal productivity I've read throughout the years, but surprisingly, many approaches that this book is teaching you were fresh and new to me.
In my opinion, it's beneficial to follow the "practice what you preach" idea with this book as most concepts given in it are easy to follow and if I hadn't then I'd have forgotten all of them after turning the last page of the book. Even though I'm early on my journey of applying in practice what I've read here, I'm already seeing the benefits of it and starting to feel like a better person.
My score is 5/5.