It's a fairly faithful remake, enough so that nothing really surprised me in it. I think it will have an effect similar to THE RING (American version)/RINGU (Japanese original)--whichever one you saw first, you like more (unless it's the Korean version, I don't know anyone who argues that RING VIRUS is the best version of that story).
I got a little off topic there. There are two main differences that make me like the Swedish version better. First, LET ME IN takes out the shocking and somewhat controversial nude scene. I can live without it, but it was such a memorable part of the original version that I kept wondering if they'll do it in the American version, and if they do how will they do it. The second difference is simply a matter of style. The swimming pool scene in the original is, in my opinion, in the running for most beautiful scene in any movie ever. They still have the swimming pool scene in the American version, but just not quite executed with the same framing, beauty, and grace.
But hey, when my major nitpick is that the climactic scene doesn't hold up against what is possibly my favorite movie ever, that's not too bad.
Running Time: 116 minutes
My Total Minutes: 211,369