For those who are interested in Audubon prints, this book is a good introduction, but if you are serious about collecting or very interested in Audubon, it could raise more questions for you than it answers. Don't expect a comprehensive or 100-percent accurate treatment of Audubon or Audubon prints from this rather short book.
Unfortunately, some of the areas of weakness are important to collectors. For instance, the approach to authentication is simplistic and by no means comprehensive. The book doesn't really address how to distinguish hand coloring from printed color, or the fact that hand-colored reproductions of Havells exist. The authors barely mention plate mark, which is an extremely valuable tool for authenticating Havells. In spite of these shortcomings, the book provides a nice overview of all the major editions of Audubon's prints with a good mix of biography, history and nitty-gritty details.
Beware, however, that brevity comes at a price -- this book has some gaps. Bannon and Clark do not mention the second issue of the Imperial Folio edition of The Viviparous Quadrupeds of North America, or the existence of a restrike of the Imperial Folio plate, The White Wolf. (You can find more information on both topics in the recently published book, John James Audubon in the West, edited by Sarah Boehme).
Information in Bannon and Clark is not always accurate -- e.g., the later edition octavo dates. (Try Ron Tyler's book, Audubon's Great National Work, for a more detailed account of the octavo Birds). There are also more significant errors. For instance, the number of prints from Nagel and Weingaertner in any given octavo quads set varies; the set that Bannon and Clark looked at just happened to have seventeen plates by Nagel and Weingaertner, but they give that as the number for all sets.
The price information in this book is out of date even though the authors include some appendices that attempt to give an idea of price inflation. Still, the lists do provide an indication of relative prices. As long as you realize that these lists represent a single dealer's opinion and experience, and that other dealers do not necessarily rank the plates in the exact way that Clark ranks them, you should find this information very helpful.
In the end, I have to say that I like this book, and often find myself turning to it for background or price information. Right now, it is the best book -- really, the only book -- available that is specifically geared towards Audubon collectors. Although that will change over time as more books come out, I doubt that Bannon and Clark will become superfluous...it is a good addition to any Audubon library.