I saw this quite some time ago, but it was on the other night again, so I watched it.
I had forgotten what a truly excellent movie it really was...
What impressed me the most was the actors' abilities to keep the movie grounded in the 1800's rather than to try to 'modernize' or 'fantasize' westerns like so many do today (recent examples are Django; Unchained and The Revenant where the directors think it's 'cool' to throw out the Eff word or have cowboys treat women like whores. Sure; that probably went on some, but like Lonesome Dove the characters in this flick have respect for respectable women (e.g. "Sue") and yet hold nothing back when standing their ground. I found it brutally honest, open, and it left me with a new respect for Duvall's acting ability, as well as Costner's (I thought KC behaved like the village idiot in Silverado)
If you haven't seen this, or haven't seen it in a while, why not treat yourself?