Take two top actors and put them in a gritty chase drama in the Wild west and you should get a good movie. Luckily, you do with this. Brosnan shakes off the campness of Mamma Mia (probably, I don't know when that was made) and Neeson continues on the bad ass image from Taken (probably I'm not sure when that was released, maybe this was the start) as they both portray two evil men driven by war and vengeance. As with most westerns of the last 20 years it really shows how down and dirty those times were, where if you weren't on your guard 24 seven you probably wouldn't be around long.
There's not a lot of love on show between any of the characters and if it wasn't for the epic scenery on show you might not really care about anything, but it kind of brings the whole thing together. And it's not like the characters aren't developed well, it's just that they're nasty. Easily one of the most 'filmic' movies I have seen in a long time. The end is very clever and left me wanting for it to just carry on..... or at least find a few more down right dirty westerns to watch.