The Killer presents a stylish front, intelligent narration and quality performances, backed by compelling cinematography.
That said, when you take a step back, its still "just another" hit man flick, leaving far shallower footsteps, than say, Leon: The Professional.
Its essentially driven by a very basic story, that's too truncated to add up to anything meaningful, partially compensated for by lashings of action packed, exposition and a degree of quality narrative.
In and of itself, its marginally better than many other knock off's but not by as much, as it might think.
In summary, offers a little extra polish but does not aspire to the iconic heights, of films that made this genre famous, in the first place.