I don't know if this posting is too late or not but I can give you my 2 cents worth. I can certainly understand your concerns and the youngest crowd I booked on a Silver Seas cruise is in their 40's. They love the cruise line pricy as you know but they just love the service. Top Knotch. However, for excitement and activities I would stick to Royal Caribbean. Heck certain ships you can roller skate around the deck and mountian climb. Younger crowd too.
Whatever you decide have a great trip
***edited to remove link***
Last edited by Kuki; January 5th, 2010 at 11:10 AM.