^I agree. Top of the Rock is a WAY better experience than Empire State. TOTR provides a better view of Central Park, it's cleaner, updated and it allows for a great view of the Empire State Building, something you don't get while standing on top of the Empire State Building Plus, there's all those dreaded lines at Empire State (from Wikipedia)...
There's a semi-fast pass option, though. Allows you to skip a few lines. Even still, Rockefeller Center/Plaza offers much more in terms of an overall experience, espeicially during the holidays. If you're going to do an observation deck, TOTR is where it's at IMO.