I bought this to get a detailed understanding of WCF and how it can be adapted; and I've found it disappointing in that respect.
My primary criticism is that the book seems to be a collection of special cases or tool-oriented tricks. For example, the first section in the chapter on service contracts discusses operation overloading, and what specific attributes/configuration you can use to deal with it - great, but I'd rather read a more fundamental discussion on service contracts and interoperability than just a few syntax examples for a relatively unlikely use case. This chapter also contains the bulk of the book's discussion on metadata - six pages - which I think is superficial for a concept that I would consider to be a chapter in its own right. I would make similar criticisms for a lot of the book.
Unfortunately (based just on reading this book) I now have a rather dim perception of WCF itself - it seems like a clumsy conglomeration of stuff with no real coherence to the design. I hope that this view improves with further experience.