Amazing views from the Top of the Rock, and not too busy once we got up there, with the voucher you can go straight in to collect your ticket even if there's a queue outside and its flexible you can use it on any day of your trip, the Rockefeller centre as a whole is well worth visiting beautiful art deco design.
Excellent experience better than the empire estate building, make sure you print off paperwork and it is correct saying what you have booked,as we had problems with our paperwork, but luckily still managed to be let in OK.
Very well organised and efficient system for getting so many people to the top. If the weather is poor, it is very easy to change your timed ticket to another day. We went up one evening after dark and the views were fabulous.