I'm a big Peckinpah fan, but only heard about this movie and it's very good reputation after seeing most of his other films. So I was disappointed when I finally saw it--it just seemed a run-of-the-mill western with fist fights and bad guys--with the exception of one long sequence--the wedding ceremony of Hartley and Drury. One poster called it 'Felliniesque'. It was pure Peckinpah.
I saw the movie recently again and it came off better. There was a hint of incest in the relationship between Hartley and her father--very risque for 1962. Edgar Buchanan gave a good speech about marriage in the wedding scene. The prostitutes were amazing to watch, their colors and attitudes. So although I wouldn't call this a masterpiece, I'd call it good Peckinpah, so give it a try.