Welcome to Cruise @ddicts.
Generally, the lower down you are, the smoother the ride. However, whether you are far forward or aft could make a difference. Pitching (up and down motion) is more noticeable at the forward and aft ends of the ship, and the thrusters will create lots of noise and vibration when maneuvering in and out of dock.
If the ship is rolling, it will be more noticeable on higher decks. But don't forget that these ships have stabilizers that reduce rolling under most circumstances.