Consider not only embarkation day, when you drop your luggage off first thing, but disembarkation, which can be a painfully slow process with long lines sometimes. For getting off the ship, I would recommend traveling with a suitcase with good wheels, not a duffle that you may have to pick up a hundred times to move it forward in the line up. You can put your bag out the night before disembarkation to avoid this line shuffle, in which case you need a good sized carry on for your morning needs.