The two main actresses look really good in this. And one of them reminded me of Olivia Wilde somehow (although I can't say why). Other than that, you also have two "horror" heavyweights in the cast. But it also feels like quite a few characters got crammed into this. Technically done very solid, but the story might have needed a few tweaks here and there to work out better.
The usual "Duh" moments are not absent, quite the contrary and of course, although pretty feisty and not always in the "victim" role, our lead women do quite a few "stupid" things. Things that go against common sense that is.
What you should check out though, is the DVD of the movie. I only heard the first couple of minutes, but the commentaries on the Disc seem genuinely entertaining! Rent it and give it a listen (the thing they say about the baby is worth the rent money alone). Not great by long shot, but still far from the worst movies I've seen.