Both Grand Princes and Golden Princess have more movement than we ahve seen on other ships. On our 12-6-03 Golden Princess cruise, ther was a lot of movement. Many people had patches on behind their ear. I, who cannot ride a bus the 4.5 miles from work to home, have never had a problem. The most motion is usually at night when they are at speed. This has an affect of rocking me to sleep. The motion will be greater on Caribbean Princess. There will be a larger area for the wind to blow on, but the beam will be the same as G.P. and G.P.
When Royal Caribbean built Voyager class ships, I believe that the upper 4 decks are aluminum rather tah steel to make the ship less top heavy. I do not know the construction of Caribbean Princess.