This is not a book that you read to become an expert software designer. This is a book that you read to discover succinct ways of expressing ideas that have been floating around your head for a while. Armed with these - almost Haiku-like verses - you can convey more easily what techniques experts use. Each practice could easily fill a book chapter or in some cases a whole book.
The book is in fact little - less than 6x6 inches. But that's the whole point - you are looking at poems, not a dictionary! If that's what you're after, you'll enjoy the book a lot. If you're not, you will feel let down and you're better off build a more traditional book on software design. The book's unusual format likely explains the bifurcated reviews. Hence I drop 1 star for caution: don't buy blindly, read the reviews first to see if it's for you.
This kind of book works much better in hardcopy imho - it's the kind of book you want to bumble around in, leaf through, pick a random page.
I thank the author for handing me one of the very first physical examples back at the IEEE Software meeting - autographed no less! I enjoyed it and come back to it every so often for inspiration!