I've never really watched any westerns, but my husband said that it hit the "western notes" spot on. I will take his word for it. The introduction credit/title sequence is a bit long, but apparently that is normal for a western. The movie is set in a time when most fights are solved by a gun fight and the loser dies, Albert is put in this situation several times throughout the course of the movie.
Seth's character, Albert, is a sheep farmer; but is not very good at his job. The premise of the movie is that he isn't confidant in anything, so he needs to build himself up. His best friend, Edward, is played by Giovanni Ribisi. He is dating Sarah Silverman's character, Ruth. Ruth is a prostitute. She has sex with men for money, but she is waiting until marriage to have sex with Edward because they are both Christians. This premise was very funny to me, and that was the point. Liam Neeson plays Clinch Lockwood, the most feared gunman in the territory. He is married to Charlize Theron's character, Anna. There is a point that I wondered why Anna didn't just kill Clinch.
Most of what I recall from the trailers isn't actually in the movie, which in my opinion leaves some unanswered questions. All in all my husband and I would suggest you see this movie. It is funny, smart, and of course there is a depth that I didn't expect.