I find that when you take a cruise when children are in school there tends to be an older crowd on the ship. Yes, I also agree that when a cruise is for more than seven days, it eliminates a lot of people who can't take that much time off of work. As for cruise lines; from what I have heard, the most upscale ones are Silversea, Crystal and Radisson, where you would tend to find a more formal crowd. If you are into gourmet dining, in the mid price cruise lines, Celebrity has the best food because of it's world renowned chef, Michael Roux. As far as activities, I find that there is more to do on Royal Caribbean. We book on mid price cruise lines as I would rather spend the money to shop or go on excursions in the different ports. I have found that you find every type of passanger on the mid price cruise lines and people tend to mix with people that have similar life styles.