My partner and I reserved a table before arriving in New York and was one of our most special evenings. The dinner was absolutely delicious and much to our surprise extremely reasonable in price!
The staff were extremely friendly and attentive, nothing was too much trouble. The bar was rather busy however this never felt like it impacted on to our dining experience as we were placed around the edges by the windows. At any time during or after dinner you are free to walk around the observation deck, which was a lovely end to our meal.
You can just go to the Rockafella for an observational view however we felt this made the most out of our evening and experience!