SALT is an enjoyable diversion, much better than most contemporary action films, and actually a nice combination of thriller and action film. There were a lot of moments I felt like I was watching a Hitchcock thriller, on steroids. Also, the movie sounded great.
There are still two problems with the film. Not enough character setup or development is the first, there's much more of an emphasis on action than character. I think this ultimately hurts the film. What little character development there is comes from cheesey flashbacks throughout the film. The second problem is that the third act loses a lot of momentum and doesn't really pay off emotionally. The final twist is kind of goofy, and there's never really a satisfying ending.
But it was still a lot of fun!