Just returned from the Dream last week and did the Western Caribbean leg. I was skeptical because of all the negative reviews so I will try and answer to what I saw from some of the more popular ones (crowding, sewer smell, chair hogs, etc.)
I am going to separate this review by day of the cruise, sorry if it is too long, but I have a lot to say about the ship.
Quick and dirty summary:
There were 4 in our group (2 Cove Balconies) and we had all cruised before. We never had slow service in the MDR, food was always hot, we were always able to find chairs on deck, and the service we received was good. We made all 4 ports and booked 3 excursions, none of which were through Carnival. The bad: the amount of smokers everywhere was terrible. Serenity is full of chair hogs. I wish there was a 3rd pool. Room service menu could be expanded.
Other then that, loved it and had a great time.