If it is the same as the Magic and Wonder, Customs clears the ship about 7:30. You can get off any time between then and 9:00. Everyone is asked to be off by 9.
You will have an assigned breakfast time based on your dinner seating on the last night. If you don't like the time you are assigned (too early or too late to suit you), you can eat at the buffet. So there's no reason to leave the ship hungry. You are asked to appear promptly at breakfast as they have a limited time to get everyone served and off the ship! You MIGHT have different servers on that last morning because your server or assistant might be leaving the ship that day, so do not leave tipping till that last morning (do it the night before as is suggested by
DCL).
Yeah, I've had one bad one too...out of 20+ cruises. Normally it goes very smoothly and when it doesn't the problem is with Customs, not with Disney.