First, let me say this: The content in this book is worth 5 stars. Leo is the absolute best at making anyone realize what is important in the world, and act on it. If you've had it with other self-empowerment books, the kind that use phrases like "thrive off of synergy" and "discover the true version of yourself" and "unlock the millionaire within you" and other absurdities that clog the self-improvement industry of books, then The Power of Less will be an absolute relief. The general mantra is easy to swallow and understand: focus your efforts on one thing and you will be more effective.
The book is simple and direct with little fluff. It's aimed at everyone, not just the big-time business managers and the yuppie type. As a student and writer, I find that 7 Habits and Getting Things Done and the like, while they're great, just don't feel like they're aimed at me. The Power of Less is, though. And it's undiluted greatness. There's no New Age-y stuff in here, nothing really abstract. Just solid, practical approaches to the problems that everyone faces.
Here's the one catch, though: at least 85-90% of the content in this book is fundamentally equivalent to what's been posted on his blog, Zen Habits (zenhabits dot net). Leo's techniques rely on simplicity so much that there are really only so many ways you can spin it.
There are a lot of reasons to buy this book: it goes a little bit deeper in its explanations, it is a great summary and introduction to everything on Leo's site, it supports Leo after all of the hard work he has put in to helping your average Joe like me make his life and his world a little bit better, and it introduces his ideas in a logical order.
But you can get explanations the same fundamental approaches and set of tips for free on Zen Habits, so if you're looking to pinch pennies while still taking serious steps forward in your life, you might instead just want to go through his site.
This review is not a knock on the book at all. It's just a reminder that there's a free digital alternative. That's a tip Leo himself would approve of.