Hi all, Holland has a well deserved rep for being senior. Since Celeb is the other premium line among mainstream cruiselines it often gets the same rep. Celeb has a little more diversity in ages but any cruise to the Med will be more senior than the Bahamas or Caribbean. I think you'll be very pleased with Celebrity, the mix of passengers and the Galaxy as well.
I get regular and very good reports on all of the above. Occasionally there is a curmudgeon among the reports but overall they are very good.
Have a great time!