People interested in non-human intelligent life can be broadly grouped as those who believe, and those who don't. Both groups have their own reasons for holding a particular position so for the most part, anyone from one group trying to influence someone from the other is unlikely to make much progress provided both parties have done their homework.
It is my belief that this book has the potential to become a classic textbook for anyone seriously interested in exopolitics and the author has clearly spent time researching. My only caveat would be that many if not all the images are already familiar to me from the internet, and may not necessarily be an accurate representation of the races described. If the author considers releasing an edited and updated version of this book, I would like to see a caveat concerning the uncertainty of proving the existence of non-human intelligence, references to encounters with the various races, and perhaps illustrations prepared by a skilled artist from the descriptions, but these are minor quibbles about what is, in my opinion, a very useful reference.