I've only been on one cruise, Princess, back in 2007. It was a ship with around 4,000 passengers. Embarking I thought was easy. Disembarking at the end took a while. They had a list of the approximate time you could get off depending on what/where you were going, but you still had to wait for them to call your group. We were at least an hour later than our listed time.
One thing we learned really early was with shore excursions, take the afternoon ones or plan your own. When you book a morning excursion, everyone else on the morning excursions is getting to breakfast at the same time, so it's a zoo. Going with afternoons, we could get up when we wanted, get off the ship for a few hours and sight see before heading back to the ship for our afternoon excursion.