I read this book quite a few years ago. It was an entertaining read, but from what I remember, the impression I got was that he talked about a lot of subjects, aliens, atlantis, etc, the whole gamut of stuff, but then his conclusions seemed rushed and somewhat lacking. Almost like he was filling in gaps for the sake of creating a neat, happy ending, which always stood out in the back of my mind. I can't go into detail about it because I literally don't remember much about this book other than that... which says a lot about the book.
Hope this helps, fwiw