I think that the consensus among cruisers is that the lower deck you are on, mid-ship, the smoother the ride. I personally prefer the highest deck I can afford. Everyone has their personal preference for stateroom location. We do try to avoid rooms anywhere near the galley, disco, Lido deck, etc. The noisiest stateroom we ever had was near the galley, there was loud banging and clanging going on at all hours of the day and night. Every cruise thereafter, we chose our stateroom carefully. We have never booked a Guarantee Room, don't want to take a chance on location assigned by the cruise line.