Just finished a Carnival 3-Day cruise (Paradise) from Long Beach to Ensenada. Here are some observations:

This is definitely a party boat. People seem to be in the mind-set of "we've only got three days".. let's party as hard as we can." In general this wasn't too bad though I did see one person vomiting in the hallway. Also, there were a good number of teenagers/early 20s and they were pretty free with the swear words.

Smoking -- If you're sensitive to cigarette smoke I wouldn't recommend this cruise. People were only supposed to smoke on deck and in certain bars, but I saw people smoking in hallways outside of state rooms, and while walking on "Carnival Boulevard." Ironic since the book in your state room, which tells you about the history of the ship, boasts of the whole ship being "non-smoking." I guess they gave up on that when it became a party boat! Read more