Here are the two comments I made while reading the book:
I am getting real sick of this book - all these what ifs and how many people there are. I'm close to done with it so I'll more than likely finish it but I am definitely giving it a bad rating.
There's an awful lot of male giggling in this book. I'm just saying . . .
So, when I first started reading the book I thought it was really good. And then there were so many what-ifs that it was ridiculous. That's when I was getting sick of the book. Then it started getting good again and I really enjoyed the ending.
I'm giving a 3-1/2 star rating because of that later redemption.
As an aside, I saw the book was published in the 1970s but there's reference to CDs and I thought did they have some giant version of a CD back then? Then they mentioned the twin towers and I went back again to see that it really was published in the 1970s. I don't know if the author amended the book without really a reference to the amendment to make the reader think he went back in time to add later events but whatever, it worked. :)