Objectively speaking, I think this film merits recommendation in most regards. It was believably told and concise enough to hold your attention all the way through. The cast did a terrific job. Though, while I'm a fan of McGregor, I felt he was miscast in his role. But that's a subjective criticism that didn't seriously detract from enjoying the film; I almost didn't even recognize him at first.
My only complaint with this film and the reason I didn't find it very memorable, was the rather droll vernacular. The verbal portion, what was spoken, had little spark or poetic finesse. Compulsorily conveying what was essential is the most it offered or even attempted. Optimistically, my guess is that was the aim, maybe for authenticity's sake. Either that or the film's origins were no more fleshed out than an idea when it went into production and the writer(s) was/weren't allotted the time to really exploit their craft. The result: a solid western, without any real panache or inspired sense of purpose, but a well told, intriguing story none-the-less.