I saw it. It's definitely different. You have to pay close attention to the entire film and probably have to watch it twice (or more) to figure out exactly what is going on. I'll be honest - I had to look up an FAQ to figure out all the plot points. I don't even want to give it away here. You really just need to go in to it blind and let the movie play out.
I liked it, but I didn't love it. I didn't really care about any of the characters and I was kind of frustrated with not knowing what was going on. I wasn't a big fan of the score, either. I know that's been a big selling point of the movie, but I just wasn't that impressed.