It is a fantastic movie... the hair on the back of my neck stood up when it came to that scene in the canyon, with everyone on bats with little machine guns, complete with "Flight of the Valkyries" playing in the background.
Overall, very well done, I'd say. There were a few times, particularly at the beginning, that didn't seem to have much relevance to the overall plot, but that might just be me, and not having seen it since it came out.