I'm not a huge fan of serial killer movies, reality based or otherwise, and if a film is going force violence on me than it better be worth it.
Chugyeogja's grit is manageable and completely worth it. It's plot is different where it counts, and the characters are perfectly written and acted, while at the same superbly
cliché. Unlike many
procedurals the director never insults his audience, and even takes care to construct the most believable foot chase ever caught on celluloid/RED-RAM. If you loved
Oldboy, High and Low, or Infernal Affairs you should be good to go. I even prefer it to the first of those; scandalous I know.
(UPDATE) As of 7.10.10 it's on Netflix Instant.