The bad guys' motives for their evil deeds was not the focus and not very clear. They were just there, needing to be stopped.
There may have been a few tiny plot holes, but it was suspenseful. I enjoyed the suspense and twists. I didn't mind the ending at all; it made sense to me, although it does leave you hanging, wondering "Well, what happens next?"
The setup in Las Vegas is a bit strange, but frankly the Philip K. Dick story on which the original draft of the movie was loosely based is also quite strange (though totally different).
Julianne Moore is exceptional as the FBI agent who has complete faith in her own conviction that Johnson is the solution to the expected attack. We have of course come to expect brilliance from her performances, and I found this one completely up to her usual standard.
Two scenes stand out in my mind, years after seeing this movie: the one where Johnson escapes from the government agents by causing an avalanche then running through it, and the search of the building that displays extremely well the way Johnson sees the world as a series of alternate futures.
to post a review. While not that plausible at times, it does have a certain cool factor, and the effects look nice enough