Instruct: Classify Amazon reviews into positive or negative sentiment
Query: One of the best golf books I've ever read, and so simple too

Great product as everyone else points out. Such a simple idea, yet so remarkably capable of fixing your swing. I didn't realize just how mush I was trying to muscle the club, rather then let my natural tempo and fluidity carry it. I'm the kind of person who needs a swing thought, but at the same time they make me stiff and awkward. But if my swing thought is tempo, i.e. proper speed back and through, I become much more free loose and less timid, the club glides along rather then feeling like I have to reroute it and muscle it back to the ball. Truly a great book.