The advice is hit and miss - some of it is very helpful even to the most advanced GM, cutting straight to the essence of tabletop RPGs, while some of it is not particularly useful except in the most extreme cases where you might be better off just asking problem players not to return anyhow. However, where the book hits, it critically hits, and does so with a tone that can cure the most doormat-like of any GM. The book is also full of many entertaining stories from John Wick's own gaming table, which makes the book extremely easy reading and difficult to put down. I can't help but wish that I had the opportunity to have a character "Wick'ed", I think it would have been one of the best roleplaying experiences that one could have.
[5 of 5 Stars!]