The Power of Habit is a very fun book to read. Duhigg avoids heavy scientific jargon and uses many real life examples to demonstrate his points, making psychology and sociology research findings behind habit formation and habit change easier to understand and digest. What sets this book apart from other self-help book is the later sections which explore organizational and societal habits. This shows that human behaviours and thus organizations and society at large can all be modified by understanding how habits form, change, and influence other behaviours.
Sometimes I feel that Duhigg dwells on the same concepts, repeatedly going over the same thing, really trying to drive the ideas home. It gets tedious sometimes, but this is rather a matter of personal taste, and I can see that some readers may absorb the key points more effectively this way.
Overall, it's a practical, useful, and illuminating book on habits, at a personal, organizational, and social level.