Can one tell a difference in the deck level for ship-sway or engine-noise. Have chance for bottem level of ship cabins but am concerned about discomfort at this level. Afterall, the penthouses are much higher.
The lower decks have less motion especially mid ship. Remember that there are usually two or three decks for employees below the ones for passengers. Noise is not an issue these days unless you are near the mechanical equipment for docking. That can get loud at times when pulling into port.
Also lower decks are easier to access when returning from port.