Awful with a side of meh.
Nothing made sense. Why were Rory and Amy there this week? What purpose did they serve beyond Amy's getting to tell the Doctor "This is what happens when you travel alone for too long." --when, as we've seen he's had plenty of other interim companions since he stopped traveling with her regularly.
Ben Browder was awesome with what little he had to do, but I think my feeling that he wasn't in it enough has more to do with my own expectation that if they were going to go to the trouble of getting someone so genre-familiar, they'd give him a role he'd be able to do something with. My mistake.
I still don't understand why it's ok for the bad doctor to suicide himself whereas the whole episode became about protecting him from the gunslinger. The Doctor says himself, in this episode -- "You don't get to choose your punishment!" -- and yet everything is hunky-dory at the end.
Pluses: The music and visuals were great. The show's DP knocked it out of the park and Murray Gold delivered another fine score.
In summation: I liked it better two years ago, when it was a movie and it was called "True Grit."