Only watch if you really got 5 hours to kill and are curious to see where this movie goes. Heaven and Hell. More like Hell. I counted about 7-8 original actors from the first 2 books, but even a few of them had little screen time.
Personally, the movie ends with Book 2. Book 3 really doesn't do anything. It seems like a filler movie that should have not been made in the first place.
There was no real drama or build up of action or new characters, so the story was indeed empty. Dealing with the post war era, there is the emergence of the KKK, a revenge plot that drags through the entire movie, some American Indian action, and other pointless side stories that are as bland as eating paper. Lots of bad acting and direction might I add.
So watch at your own discretion and prepare for disappointment.
Do yourself a favour. Watch Book 1 and Book 2 and use the Book 3 dvd as a coaster.