Jodi, are you referring to one of the cabins at the curved part of the deck? These have a different layout than the category C cabins you'll see on NCL's Web site. For one thing, the window is slanted, as you can see in
I took a few years ago. (The photo is actually one of the AB suites nearby, but you get the general idea.)
We've been on Majesty Deck, although slighly aft of where you'll be, and it was a good location. I don't recall hearing runners above...it was a long time ago...yet I do know from my recent trips that the running deck is made of some sort of squishy material (I am not the wordsmith today, sorry). There may be some motion on this part of the deck depending on the weather, yet there are plenty of remedies if needed.