We booked this cruise to join a group of neighbors who were all going at the same time. I was apprehensive at being on a ship with 6,000 passengers but those who had been aboard told us that because of the huge size of Oasis you'd never feel crowded. They were right!
RCCL has figured out large ship cruising. The embarkation process was very smooth. Our status as 4 time prior RCCL passengers got us to the check-in counter with no line but even the first-timers were not waiting long. We booked an outside balcony and believe it was the right decision. The "inside" balconies facing each other across the Boardwalk seemed like you'd have more noise, less view, and sort of like living in a highrise looking at your neighbor in the next building. The high tech stuff is great. There are touch-TV screens at all the elevators where you can find out where you are, where you want to go, what's happening, etc.
Don't pick this itinerary if you want to experience the Caribbean. The destinations (RCCL's Haitian resort called Labadee, Falmouth Jamaica, and Cozumel Mexico) are nothing special. The experience is the ship itself. We booked all the entertainment venues before we boarded, and its a great system to insure you'll get a seat. They included "Cats" the Aqua Show, Ice Show, the acrobats, etc. all fantastic productions.