This book is alright. It has extensive details and tries to keep an objective POV on the reports and sightings.
However it makes a strong emphasis on the late 90's UFO autopsy video, which has since been debunked as a hoax.
Therefore, most of the details and speculation in this are trivial to read.
Therefore, this book feels somewhat antiquated by recent events in the past 10 years.
The first edition (2010) printing is misleading, as it was originally published under a different company in the 90's. Someone hopping for any recent revelations on the topic should go else where.
The price tag on this is definitely not worth it. Maybe 9$.