I can understand why they say it "rocks" on the reviews
Carnival victory is almost the same size of the carnival destiny and I have travel 3 times already on it on the same route.
Here is the deal st.Thomas and Dominica are no trouble but the main trouble comes after Dominica during your travel to Barbados as soon you enter the Atlantic it gets to a no good for confort situation. My advice take a little dramamine just after you get out of Dominica, but remember a little, they had them free on guest relations or better yet bring them with you just in case.
The caribbean is a nice calm place during "navidades" winter it's at 75 degrees in most of the island you will enjoy it and welcome to the Cruise life...