I've been on QE2 to Europe- 3X on Carnival and 2X on Princess. All 7 days or longer. This was my first time on RCL.
What I liked/loved:
1. The promenade deck is gorgeous- just like a real mall
6643- Great location. Close to Promenade, all dining rooms, and Casino. Not too close or too far from the elevator. It was very small compared to other cruise lines. The showers are great, as the doors actually close and water doesn't leak out. The closet space was just so/so, but we made it work.