If you're looking for a book on leadership that tells things as they are, without tons of fancy formulas or advice that is hard to apply in the real world, then this book is for you.
Leadership is an art more than a science, but there are some universal simple rules that anybody can follow in order to be a better leader, and this book covers them all in a very comprehensive, yet succint and specific way.
You might not agree with all of Jack's ideas (I certainly don't), but that is what leadership books are for: generate discussion rather than claim to be "the truth". Use what you think is valuable, and discard the rest. Whatever you do, this book gives practical advice, and I see a lot of value in that.
Particularly good are the chapters on Career Management, which are not always covered (or not covered well) in leadership books and yet are an esential element in the success of any leader. Books like "What color is your parachute" are more comprehensive, of course, but "Winning" has some down-to-earth advice in this area that I found very useful.