While the talent of dubbing actors is often very good, it is still exceedingly rare that a foreign language, no matter how well spoken, can convey the ideas of the native language without coming off as a little detatched, or otherwise a bit hammy. With that in mind, many people absolutely can't stand subtitles, in which case it would be best to watch it with dubbing, should you be one of those people. Unless you either wish to hear the voice dubbing, or don't want to read subtitles, it is definitely a superior experience to watch this film in its native Korean.