Absolute garbage. I get that the author starts from the premise that there are aliens who have been in contact with humanity, but that does have to extend to believing the wild claims of every crackpot out there. But, or course, they aren't crackpot in this world view, they are all highly esteemed and respected people who are at the top of their fields (even though no one has heard of them). And, of course, the friend of a friend of a friend, can't forget that valuable source of information.
If the poor scholarship was the only problem, I could probably give it a higher rating, but the book is also rife with poor sentences and even some spelling/grammar errors. Maybe next time splurge on an editor?