Great movie, though I think that Asia has all but over-killed the gangster genre. It's the typical plot we've seen time and again, though there is a little bit of character development throughout the film. The few action sequences were over pretty quickly, with one or two lasting a bit longer (re: 20-30 sec). I did enjoy the film, though I think I went into it expecting too much.
As to the previous review stating that this is better than Kill Bill... don't believe it. We went to see Kill Bill for the action (which it was loaded with), so comparing this film to Kill Bill is akin to comparing Star Wars to Star Trek Deep Space 9, or Pulp Fiction to 21 Grams; yeah they (my example) may follow some similar plot themes, one set a space theme, or the other set following disjointed time-lines, but that is where the similarity ends. This film was nothing like Kill Bill except it has assassins in it.
Bottom Line: It was a good movie, but don't go into it expecting anything but an Asian gangster cum assassin movie; there is nothing special beyond that.