Six hours, read by Sean Pratt, is a manageable shape for a book meant to be used rather than admired. The early ratings are warm, though the sample remains small, so treat them as an encouraging signal rather than a settled verdict.
Approach it as a working title instead of a sit-down read: the sections are the kind you return to once a term, when a decision needs backing up and instinct alone will not carry the room. Anyone teaching, coaching, or running a team whose results are measured will find the ground familiar. Have a scroll through what is listed below.