I thought it was a great film. Was it really 2.5 hours long? The time just flew by.
Dover certainly didn't seem like an anti hero to me. He had no redeeming qualities whatsoever. In fact I don't think there was a single character in the film other than the children who were anything other than unlikeable.
That being said, it was thought provoking. But even though I tried to put myself in Dovers position I just couldn't. In my mind he was as much an animal as the abductor.