The only time it felt crowded was the night of St. Thomas. I was in the atrium as the 6:30 dinner was getting started and felt overwhelmed by the number of people there. It seemed that between the shows, the photo ops, the characters, the stores and dinner, everyone on the ship was there at that minute.
But other than that, it was fine. If I ever felt crowded, I just went ot my verandah.