I love Brad Pitt and saw the movie because he was in it - but I liken it to Fight Club. If you're not into blood and gore, don't go and don't take young kids. I think all of the actors gave amazing performances, I just don't believe we have to see every gory detail. I also didn't understand taking a well known historical time in histroy, using real historical figures from that time, but then changing history entirely. Just my opinion.
I read the book years ago and went to the movie with my husband whom had not read the book. I agree with the other reviewer's that reading the book fills in a lot of the holes and questions you have by watching the movie. That said, I still think they did an excellent job adapting a very complicated story and idea to the big screen. Rachel and Eric do an amazing job of making this seem plausable. The child actors also do a wonderful job. Worth seeing - bring your tissues and your imagination.