While this volume is over 800 pages from cover to cover, half of it is notes and works cited. Like Keener's other works (I’ve also read his commentary on Matthew) this volume on the “Historical Jesus” is filled with extra-biblical citations and observations. Keener’s expertise in socio-contextual study makes him a force to be reckoned with (even if this is his first work devoted to the topic). What I appreciate most is Keener’s firm grasp on “Historical Jesus” methods and paradigms, and his ability to use them responsibly (Keener's book could be used as a guide in my opinion). Keener levels serious critiques of some of scholarships earlier works (Crossan, Mack, the Jesus Seminar, etc.), while building upon the works of some influential scholars (Sanders, Davies, Hurtado, etc.). All-in-all I think Keener’s volume is indispensable, especially when read alongside other works on the same topic.
I can’t recommend this book highly enough as a foundational primer for contemporary Jesus studies. In one volume the reader gets 5 views, each with 4 critiques (from the other authors). By the time the reader finishes the book, he or she will have a basic grasp of the discussion and its primary points of argument. What is likely the most helpful contribution of a book of this nature is that each opinion is balanced by its critiques. While not perfectly, it forces the representative scholars to wear a rhetorical seat belt. If you want to know what people are saying about the Historical Jesus, than this is the place to start.