A strong premise and great cast prompted my interest, but the movie falls short of its promise. Clive Owens gives a great performance and a few of the scenes are remarkably memorable and resonant. However, there are very long stretches where the movie simply stagnates and the plot drifts away, especially towards the end. Overall, it's rather melancholy and despite the "action" scenes, not especially thrilling. If you like sci-fi movies set in dystopian futures, or are a big Clive Owen fan, you may still find it worth watching despite its flaws.
An aside: One of the "extras" on the DVD has some heavily accented academic trilling at length about the movie's philosophical meaning. It's entertainingly over-the-top and almost unintelligible: jargon piled into a Dagwood sandwich of contradictory abstractions. Anyway, if you don't watch too much of it, its good for a laugh.