The first half of the book is more informative than the second half. Most of the second half are fillers.
The thesis of this book is that there are two types of communication. One is language from the center which:
1)Directs rather than responds
3)Contextualizes with authority
4)Contradicts, argues, and disagrees
5)Practice affect of control.
The other type of communication is language from the edge which:
1)Respons rather than directs
3)contextualizes with strategies
4)avoids open argument
5)Practices conversational maintenance
To be an effective communicator, one must know how and when to communicate effectively in either styles. The book provides insights on how and when that might be.
Overall, reading this book and applying its methods will make you a better communicator, but probably not by much. But improving your communication even by 5-10% will probably make a difference in your career and life. So I recommend this book for its worthwhile content and methods.