Who else agrees that this was painful to watch

The first hour was indeed very slow. It picks up considerably in the second half.

I found the incompetence and crudeness of the detectives to be mostly annoying and frustrating (rather than humorous, which I believe was the film-maker's intention). They got their act together a bit more in the 2nd half, which made the story more gripping.

The way I see it, the director is making fun of the "rural" judicial/police system in 80s South Korea with a gripping story. I imagine the majority of people who dislike it arrive at that conclusion simply because it doesn't have an American style "perfect" ending where everything is solved and put in place for the simple-minded viewer. I hope my comments don't offend any of the aforementioned simpletons.

Before you get blisters on your fingers from any angered feelings I may have stirred as you type feverishly in incandescent rage, think about the movie "Mississippi Burning", which is set in the USA in the mid 60s. Anyone not familiar with this particular piece of history would think this movie was absolutely absurd, how can people possibly be like this less than 50 years ago?? So perhaps you should look into rural South Korean history and educate yourself as to what went on there in 80s.

"Does Barry Manilow know that you raid his wardrobe?"

I guess I never saw it as "corny" because I picked up on the grim-but-humorous tone right from the start. Which, admittedly, is a difficult balance to pull off - maybe more so in a foreign-language film with subtitles, the format in which I viewed this one (started with the dubbed version for a couple minutes and couldn't stand it). Unlike the old Jackie Chan flicks (which you mentioned) I never found myself rolling my eyes or laughing at unintentionally funny scenes. Mostly I just found the movie compelling enough that I could totally buy into some of the sillier (with hindsight) plot details.

I agree that the cops (including the main character) are lunkheaded bullies, and obviously depicted that way on purpose. And while I could be wrong, I took this more as a reflection of their character as individuals, than as any kind of overt social commentary.

As for the primitive and often inept detective work, again, I tend think that was the whole point. These mid-80's rural cops are working without so much as basic computer equipment, let alone cell phones or Internet, and this combined with their decidedly non-intellectual/non-introspective nature, makes for rough going to say the least. While many of their actions throughout the film are deplorable, their behavior seems more rooted in desperation and anger than innate sadism.

8/10 (very good/excellent)

P.S. Sorry for the long-winded post.