I was very lucky when I watch this movie at TIFF(Toronto International Film Festival) and see the actors and directors directly too. The movie is just amazing. The city design was made by computer and looks very realistic. The action is also top notch and the end was pretty unpredictable.
There will be a lot of blood in the movie. If you are weak to such movies, then don't watch it (it has some brutal and disturbing scenes).
I like the fact that the lead has some flaw in his character. He is by no means a good cop. But by the end of the day he some good points and what happened to him is just some tragedy. One of the best Korean suspense and thriller movie.