I think I must be the only person in the world who kinda liked Duck. Despite being an obvious foil, I thought his relationship with Don was always more complicated than the typical asshole/white knight thing you see on TV. Indeed, Don was often very much an asshole. I even liked his relationship with Peggy. He was the only dude on the show who seemed to desire her in some whole sense—he thought she was beautiful, while at the same time recognizing that she was gifted. Those qualities never seemed in conflict in Duck's eyes.