Well laid, efficient even with 100s of people, clean & thought-out. The only thing missing was a clear view, but we were warned about the fog before going up and we still saw 5+ miles out by the time we ended our visit. Theoretically, we were supposed to be time-limited, but when it's not crowded in the mornings, no one bothers you. Both of our visits were in the semi-foggy mornings.
Of course, the entire 9/11 neighborhood has lots of things to do and see and to some extent, represents the future entertainopolis of New York City.