We chose Oceania for the timing of the cruise. As we sailed and completed our cruise on 12/22 just before Christmas.
First the ship: The Riviera is a beautiful ship. Well appointed public areas. Nice pool deck and fitness center. If you want a rock climbing wall or are traveling with kids, Oceania is not for you.
Cabin: We had a veranda cabin. We found it well appointed and spacious, with probably one of the biggest bathrooms we have ever had at sea. The room at 28 sq/ft is as large as a mini suite on many other lines.
Great room, good size, well appointed.
Key West is Key West, go walk around and explore!