I stayed in 2500 (farthest forward room possible, starboard side) a couple weeks ago. I'm not sure what caused it, but there was a thumping noise almost all night, each night. It was once about every 10-15 seconds, and reminded me of a loose sliding closet door sliding back and forth and bonking the wall. I don't know if that's what it was, but that's the image I had in my head every time it happened. It kept me from sleeping easily. We had family in the connecting room so I could confirm it wasn't their closet.
Also, the elevators seemed to take forever to come down. I'm not sure what algorithm they run on, but it was quite a wait. This may actually have turned into a good thing for us because it really kept us to our "take the stairs!" mantra. In addition, once you did get on you stopped usually on decks 3 and 4 as well.
The nice thing was being able to walk right up the stairs to the Walt Disney theater, and be super close to the disembarkation points.