Well it's really is up to you. I have been on 9 Carnival cruises but never on the same ship. I like to find the really best deals too. November, December you can find last minute fares on Carnival for $299 per person for 7 days just be ready to book on a Tuesday or Wedensday and leave that weekend. Plus I am only 211 miles from Miami so that helps alot no airfares needed here. I have also been on 3 Ncl, 4 Rccl and 1 Costa (never again) and 1 Princess. I would like to try the Allure of the Seas some day It really sounds great. I also think the Dream, Magic and Breeze will be great ships to explore too. And make sure to purchase one of those "Future Cruise certifacates" on the ship.
A free 100 dollars shipboard credit on you next cruise. I will be using one for my November Cruise for sure. Ed