To be honest, some of the tips that are given to them are not stupid at all: in terms of time management, assertiveness, or for greater work efficiency.
By cons, if negative, I find that contains the book by saying: "it's nice stuff, but it's impossible for me!". Because it is still all swing overboard: work, friends ... the announced goal is to adopt a "nomadic" life, an expression of true wealth.
That's why "The 4-Hour Workweek" seems more appropriate for singles, young and adventurous. If you do not think you have these qualities, you will have a good read, but your life will not change.!