We only done 3-nights and are going on a 4-night this time. I would say the longer the better, since we never want to get off the ship at the end! We would have done the 7-night this summer, but since the Magic is not in the Caribbean we decided to do the 4. Also, if you are doing the parks, too, and you only want to be on vacation for a week, you have to do the shorter ones. It is hard for us to be gone longer than that due to my husband's work, dogs in kennel, kid's sports activities, etc. I think the shorter ones are also nice "introductions" to cruising if you have never been before. I would also be interested to know if people like east or west on the 7-night, since we would definitely do one of those in the future. STLDisney_Freak, I am a Mizzou alum, it sounds like you might be, too.