I've had a copy of this book for so long, but it reeks to me of something that should be a blog post I can read in 5 minutes, and so I've never been able to muster the interest to crack it open.
I find many "productivity" books tend be easily summarizable... but reading the book is really to drill the concept in your head so that you're conscious of the tips/advice in your day to day.
Plus, if you spread out the reading over a few days/weeks, you can apply what you've learned throughout the day as you read along.
How seriously would you recommend it?