I have been on 8 cruises, including RCCL Oasis of the Seas, Freedom of the seas, Norwegian and some other carnival/RCCL ships. We chose the fantasy due to the proximity (we live in NC) for my mom's 60th birthday. We had 13 total people, including 2 that upgraded to the owners suite which was awesome!
We booked adjoining cabins on the Upper deck and were happy with the space. After reading lots of reviews we were prepared to be disappointed, especially after cruising on Oasis and Freedom, but we had a great time. The size of the ship was nice, I loved the pool deck tropical theme, and the ship was very well maintained. My son loved the waterworks slides as well. There was plenty to do including a decent amount of bars to visit. The shows were OK (the hasbro game show was really bad) but for cruise entertainment it was fine. We did the alcohol package and it was well worth it. Overall we were pleasantly surprised and would definitely do this cruise again.