I found this film quite remarkable on many levels. For one, it was the debut for Brando as director (and his only film direction since). Reportedly, it was taken after Kubrick left due to altercations. Well, this time, Brando has one foot in front of the camera, as well as one behind it. He does a great, solid job. In fact, this film never looked awkward or misguided -- it felt like an intelligent western helmed by an Anthony Mann or Raoul Walsh. To further boost the professional polish of the film, there is cinematographer Charles Lang (Magnificent Seven, How the West Was Won).
Within this polished piece of work, the muscle of the film is found in the wonderful character study. Here, the characters, like in many great stories, are complex, dark, tempermental. Although the film is about the hero's(or anti-hero's) thirst for revenge on a man who done him wrong, there's a romance in the film that is truly tender and fateful.
The magnet in this film would have to be Brando. (Karl Malden is great too). Brando's understated performance is of the subtle type, using his famous darting eyes to penetrate the characters and the viewer. He's one of my favorite all-time actors.
As with all great films, One-Eyed Jacks is a quiet masterpiece, displaying what every good film needs: great script, powerful acting, layered characterization, and be technically-sound.