Though I am rating this at a 3, it has more to do with the nature in which it is written than the content. As a writing instructor, the material included in this is useful and thought provoking, approaching certain assignments in a way I have not encountered previously--but the book does come across as a tad too authoritative and didactic, and certain exercises are repeated too often.
A useful tool, regardless, but one to be used in a manner that suits individuals' teaching styles.