We were in 6590 on the 12/6 Western last year. About four days into the seven-day cruise, something in that wall (with the trunk/indent) came loose and banged non-stop all night against our wall. We couldn't sleep at all.
The next morning, a sea day, I spent an entire morning and part of the afternoon dealing with Guest Services, trying to get them to investigate and fix it. When they said they would have to remove our cabin wall and release a bunch of dust into our room, we realized we had to put up with the noise or move mid-cruise. We chose (?) to move and they upgraded us to a Cat4 (from Cat6). Big whoopee, for two days.
We lost more than a 1/2 day of our cruise and they compensated us with $200 for our "minor inconvenience," noting that the upgrade was worth so much. I disagreed that the upgrade was worth anything, because we were moved to 8000, which was a far worse location, and because we had a bunch of confusion around tipping our different cabin stewards, because we had to pack with an infant, etc. But they acted like it was a big gift! Anyway, my prime satisfaction came from the idea that at least the next cruisers in 6590 would not have to deal with that.
But until the very last person we dealt with at Guest Services, everyone else was a total idiot, no one knew what to do, who had already been called, what had already been done, and miraculously, everyone whom I'd spoken to previously (I kept names) was "on break" or "off duty" whenever I called, so I had to keep telling the entire story from scratch.
So, yes there are some large wiring conduits that run through that wall, and it is a quiet room as a result because you're separated from the room next door, except if something goes wrong. It's close to the laundry but the only slightly annoying part about that was the immense heat and steam that poured out of the laundry room every time we walked by.