I am a person who sincerely questions the infallibility of the Bible. However, this book serves to make one briefly wonder if there is some truth to those anti-Christian conspiracy theories.
This book claims that Q had three editions. The author does not present the methods used to determine which "sayings of Jesus" from Matthew and Luke belong to which edition of Q. From what I see, the complete book of Q presented seems to be only the common material from the gospels of Matthew and Luke. It is possible that there was more material in the actual Q document that was not referenced by either Matthew or Luke. And it is possible that some common "sayings" material did not come from Q. This text makes no comment on such obvious possibilities.
The author makes numerous claims about the motivations of the writers of Q without presenting or referencing any evidence that supports his claims. For example, while the author does effectively demonstrate that some of Jesus' sayings follow the Cynic tradition, he leaps to the conclusion that the original "Q people" considered Jesus as a cynic sage.
Another major shortcoming is the author's tendency to present certain viewpoints as facts rather than interpretations or theories. For example, he states as fact that the marketplace children had "rejected the Jesus movement" using as his basis the Matthew 11:16 and Luke 7:31 passages where Jesus uses an analogy featuring teasing marketplace children. I must admit that was an interpretation I had not encountered before and in the context of the surrounding verses the author's interpretation is a little far-fetched. My main complaint is not that the idea of the marketplace children rejection it is far fetched, but that the so-called rejection is presented as a fact not as an interpretation.
The book is thought provoking. It raises some serious questions that deserve some sincere, objective answers. If one is searching for "scholarly", objective answers maybe there are some good books that will provided those types of answers. This is not one of them. Keep searching.