As a lifelong NYer, I just went to Top of the Rock for the first time yesterday (with visitors from France ) and I have to say it's light years better than the ESB. First and foremost is that you get that great view of the ESB. (The view of the Chrysler Building, however, is obstructed by the MetLife Building from this view).

The lines are smaller and the interior wait area is much nicer than the ESB. (Employees were friendlier, too.) The elevator ride up is very cool with a glass ceiling and 'light show' as you ascend.

Top of the Rock has 3 viewing levels and you can get great photos from all angles. They also offered a AAA discount. I would do this over ESB any day.

Have a great visit.