Robert Duvall's career is a funny thing. He has very peculiar role selection, with a strong tendency toward playing tragic heroes, looking for redemption and living in the long shadow of their own mistakes. Examples of this include The Apostle and Tender Mercies. Not all of his films are like this, but he has the most curated career of anyone I can think of. Get Low is a film cut in this mold.
Everyone lives with a few regrets. We all have a few memories that make us twinge; maybe we all need therapy. Duvall's character in Get Low has lived an isolated life for four decades as penance for an unknown but oft whispered about transgression. The plot of the film revolves around the secret that kept him alone for all those years.
The plot moves along nicely, with revelations about the terrible secret moving slowly, but a talented supporting cast keeping things interesting.
All in all, it's not really the kind of film that appeals to me. Throw in a boob or a robot, of a boob on a robot, then call me. For a more urbane audience looking for a good plot, good performances, and a good payoff at the end, this is just what you're looking for.