That's another user or commentator, here on IMDb. And his last sentence is "Go and watch the movie". I fully stand behind this, because this was one of the best movies I've watched this year (at the Fright Fest in London).
There's only a little thing that you should bare in mind: If you actually don't like Korean (or Asian movies for that matter), than this won't be for you. Especially if you like your movies to be according to a somewhat linear structure. While with other movies of this nature, you might foresee things happening, I was baffled (in a good way) with the directions this movie took. Very brave choices and a great script. The actors of course are phenomenal too. It all fits together in one whole perfect piece. If you like your thrillers to be ... well thrilling, than this is the one to watch!