I have never been on the Serenade, but if you like smaller ships, I would try the Summit. The Serenade looks to be about 600 more pax capacity than the Summit.
IMHO the service on =X= is amazing, which makes for a better cruising experience.
We really enjoy the Concierge Class level on the M-class X ships, too. Do you know which cabins / deck you're interested in? We're familiar with many!
