My very first cruise was on the Sovereign. Back in 2004. That just before they spent more than a few million dollars renovating her. I had a great time. Now that the ship is renovated, it will be even better.
CocoCay was a nice little private island of Royal Caribbean. They had a amazing beach on the island. In the middle of the island was a large pinic area, and just like onboard all the food was complementary(OOps!); I should say "include with the cruise fare".
I have been to Nassau twice on two different cruises (once on the Sovereign and once on the Carnival Glory). My favorite thing to do there was to go to the Atlantis Casino and Resort, which is across the channel on Paradise Island (visible from the cruise ship docked at Prince George's Wharf). The underwater aquarium at Atlantis was amazing!
I hope this was some help. Have a nice time on your cruise