We just got back from a cruise on the Royal Caribbean Oasis of the Seas ship out of Ft. Lauderdale. A week long, stopping in Haiti, Jamaica and Cozumel.
Pros were nice ship, clean, staff and service excellent (waiters, bartenders, photographers, housecleaners, etc). Entertainment was good with olympic level divers in an aqua show and comedians good. We enjoyed the casino at night. Food was good for breakfast, average otherwise. We did the unlimited drink package and it was worth it. We did the longest zip line over water, 500 feet up and about a mile long, at Labadee, Haiti and that was awesome. Decent fitness center but crowded. Onboarding and offboarding the ship was very fast and efficient. The best part for me was spending a lot of quality time with my wife and daughter, especially without phones/texting as wifi was very limited and international voice and data charges prohibitive.
Cons were the 3 destinations were not good, especially Cozumel which was trashy touristy, very crowded and no decent food or beaches (that we saw). At each island the locals were waiting for the passengers and were very aggressive hawking their goods and services. We did find some cool souvenirs to remind us of the trip. The ship was too crowded for me, about 5000 passengers and 2000 staff. Took almost 2 hours for dinner due to lines and busy, but very nice, wait staff. On the cruise days at sea the five pools were all packed. With that many people, as you might imagine, there was every body type and bathing suit imaginable swimming in those pools. You literally could not fit into the pools on the days at sea due to the large crowds. Tough to find a poolside chair as well.
We probably would not go back on this boat but are interested in trying a smaller ship that is more upscale cruise possibly on Celebrity. We thought Royal Carribbean was nicer but it was only better than Carnival per one of my daughters.