Let Me In had better acting and better characters. It was hard for me to like protagonists in the foreign movie because they were just so creepy. I know that they weren't supposed to be perfect characters or anything, but they can't just put some unlikeable characters as the main characters and expect the audience to tolerate them throughout the movie.
They made the dad and the little girl seem like complete idiots, like they never killed anyone before. Draining blood in a pretty much open field? Trying to commit a murder in the school? Attacking someone and sucking their blood right in front of bunch of apartments? Really?! The pacing seemed a lot better on the domestic film as well, the foreign film seemed to have a lot of dull moments, while it wasn't a problem with the domestic film.