Went to see this with a girl. She thought it was shithouse, and I liked it. She accused me of only liking it because of the boobs. Not entirely correct, but not entirely incorrect. Entirely awkward though.
I liked how the film flips your expectations about various characters' motivations around a lot. Some might say it's a slow moving film, but I think it's a good pace. Keeps a nice feeling of mounting dread going.
See it if you like scary giant planets. Avoid if you only watch von Trier movies for the genital mutilations.