I enjoyed it and really liked the original (old enough to remember when it was groundbreaking). I agree with others who felt it took a sharp turn towards suckage in the end, primarily because it was never adequately explained what happened to Tron, or what motivated him to turn and turn again. That was a big ass missing piece of the plot that was seemingly eliminated to keep the running time down.
But still, it was way cool. Looking forward to the next one.