I spent 4 days on the Norwegian Pearl with a group of 11 other college students. We chose this cruise for its price, and because it would allow those in our group who were under 21 to cruise without their parents (we would have chosen Carnival instead had they allowed it, I think). But this ended up being a really nice choice and despite some hurdles we all had a great time.
The purchase and online check-in were pretty painless and straightforward. The cheapest option was to split our group into three groups of four in interior cabins. As Florida residents, we weren't interested in spending time in Tampa so we showed up close to departure. The check in process was pretty painless too, except for one member of our group who is in the US on a student visa. The check in desk bungled her process pretty badly and kept repeatedly telling her that her papers were expired even though she had everything together and it clearly said on the front of her papers that they weren't set to expire for quite a while. She spent a good half hour scared that she wasn't going to be allowed to get on the ship.
When we got onboard we went straight to our cabins, which were a little cramped but still comfortable. Our room had two twin beds set up when we walked in and when we came back later our luggage had shown up and an attendant had set up a third bed in the middle and pulled a fourth bed down from the wall. Everyone had space to sleep but it was a little tricky managing four people plus four people's luggage in such a small area. It was a little disorienting to wake up at 10am and have your room be pitch black, but that comes with the territory of not having a window.