Every review I've read has given it a favorable write-up. Just looked it up on Rotten Tomatoes and It has 93%. That said, I will definitely be in attendance this weekend. I'm particularly looking forward to Chloe and Kodi on screen together.
I recommend paying First Showing a visit to read/watch (they have some video) the review from TIFF. I thought they did a particularly good job of covering the film. Note: they reference some scenes from the film in the review. You can actually see a couple of those scenes on "OvertureFilms" YouTube channel. E.g. the car accident scene is on there.
http://www.firstshowing.net/2010/09/...ble-let-me-in/
**Read Staci Layne's review as well (horror.com HP). She made a great observation about the film's score.