This is a short book, with a lot of good points in it. I especially like the section on creating character agendas in opposition to create tension in dialogue.
I think the main reason I didn’t connect very well with this book was because the author kept using examples from old movies I’d never seen. Often, it felt like the author was gushing about how great a piece of dialogue was more because of some nostalgic connection he had to it than the dialogue itself. When I read the quoted text I didn’t find it nearly so engaging as he made it seem.
Examples aside, the advice in the book is very good, and well worth a quick read.