This was enjoyable at best, ridiculous at worst and falls somewhere in the middle, hence my score of 5.
More like 4+, but I digress.
As some other reviewers mentioned the story of Bob / Barbra was by far the most absurd and should not have been included. The man and wife who tell the story said Barb got very agitated when he said "oh your DB Cooper" but then at some future point in time still allowed him to comb her hair, put sunglasses on and take her picture to show the resembalance to Cooper, a picture that was then destroyed? Not buying it.
The niece's story was comprised of suppressed memories, so I do not find them credible. I do not think she or the women in Florida or any of the people were lying as some people have suggested. I think they are remembering things the way they want to, or the way that fits their particular narrative.
The copycat hijacker seemed most plausible to me. But why did he have a gun on the second flight when no mention of a gun was brought up on the first flight. Also I would have liked to have the stewardess and the college student from the first flight give their impression of if they thought Floyd was Dan Cooper.
Raises more questions than it answers but added some new twists I had not heard before. Not bad for a rainy day when nothing is on.