This film seems to be caught between the 1950s western movies and the Spaghetti Westerns later in the 60s. While the 1950s hero drawn into conflict was 'minding his own business and wanted to be left alone', once crossed the bad guy found he woke a sleeping giant. Perhaps this style was how America saw itself after Pearl Harbor.
"The Appaloosa", on the other hand, has a different style. While Brando was minding his business before being drawn into conflict, the theft of his horse occurs while he is drunk and unable handle the situation, and he seems to be inept. It is a long scene and one that ends in humiliation for Brando's character. Even if a 1950s hero was caught off guard while being drunk, he wasn't humiliated. A 1950s hero would not appear inept, just that he had made a mistake that allowed the bad guy to get the upper hand.
There are other instances in the film where Brando's character doesn't act as a 1950s hero: his ridiculous Mexican accent, his initial plan at the gang's hideout to leave with his horse, his arm-wrestling scene, his reluctance to take revenge. Brando's character was more in style of the 60s make-the-hero-more-realistic and less larger-than-life. He doesn't win all the battles. There is nothing wrong with this, as long as you interested in watching this.
I was fine with it. I did like the final gun battle as it was different from the usual face-to-face shootout.
I had problems with Brando's mumbling. His character didn't seem laconic, but someone who couldn't express himself. While he did have some good lines, other times he seemed to ramble.
The "in disguise at the bar" scene should have been cut. The conversation left me confused and the fake Mexican accent was irritating. This scene only served to introduce one of the outlaw gang members and could have been done another way.
I enjoyed the scenery, that Brando's character was a religious man without it being central to the movie, his intelligence in the final gun battle, and the motivations being believable for the conflict: the bad guy's pride and standing before his gang, and Brando's need for this horse in his future plans.
