We flew in the day before our cruise on Oasis with several people going on a Holland America cruise leaving that day. As you can imagine, we felt their pain when the flight had mechanical problems and was delayed in New York. We will never know if they made it. Our rule number one is fly the day before, and in winter three days before.
As everyone says embarkation was a breeze, we arrived at 11am and were allowed into rooms at 1Pm, luggage arrived in a timely fashion, no problems there.
What we noticed when we tried to have a lunch in Windjammers was that the ship had 6000 passengers but some areas had roughly the same room as Voyager which has half the passengers. Windjammers is one of those places. With an army of people trying to help you find a seat, even that was mission impossible. The idea was to ask you to try other venues for food.