We recently returned from an 8 night christmas cruise on Voyager of the Seas - yes, this was the dreaded cruise that everyone was up in arms about missing Lifou on Christmas Day.
Embarkation was reasonably smooth, on arrival we were advised that check in was behind schedule and we couldn't board immediately. This shouldn't have been a big deal really, but the way the information was delivered really was very poor and not handled well at all. In hindsight I realise this was not RCI staff, rather it was staff from Intercruise who handle the check in. Nevertheless, it left a nasty taste in our mouth, and at that stage, we weren't even on the ship. Once we were able to board, it all happened reasonably smoothly ( or so I thought) and we were onboard inside of an hour.
Being a christmas cruise, the ship was obviously full. However, we had no trouble at any time finding deck chairs by the pool, finding a table at the Windjammer or lining up to get drinks. Yes, from time to time it was busy, but I think I never waited longer than 5 minutes at the bar to get a drink.