We stayed in 6588 during our 10/13/01 Magic cruise. The room was fine most of the time. Being directly across from the laundry did pose a few problems.
*Trying to catch a nap one afternoon when I heard banging on the door. Went to answer it and found a toddler hitting it with a plastic hammer. Mom was busy folding or ironing or something. The Mom noticed the third time I opened the door....never really said she was sorry.
*Noticed noise and alot of foot traffic 1/2 hour to an hour before the formal and semi-formal nights. Everyone needed the iron. So people stood in the hallway in line and talked.
*If the dryers were all being used, we could feel warm air coming in under our door. We were also able to see the laundry light under the door. We placed a rolled up towel at the bottom of the door and solved both problems.
BUT..........
We did not pick the room location. As a surprise for my DH & DS I asked for an upgrade at checkin. We only paid an upgrade fee of $358 from cat 10 to cat 6. Originally, we were quoted @ $1000 extra. So I was just happy to have a cat 6 room which was both my DH & DS's dream.
Our neighboring rooms were very quiet. We never heard anyone except those visiting the laundry. My DS always had the TV on, so we usually never noticed.
Your in-laws will probably notice some foot traffic, but it can't be any worse than being next to the aft elevators.
Even with the few inconveniences I feel that any room on either ship is better than sitting at home for a vacation. LOL
Have a great cruise.