We were in Cabin 5150 (last passenger cabin all the way aft on the Port side) last week on the Magic and it was noisy at times from the engine....it actually did not bother me, but I was aware of it. It is sort of background hum and you could also feel vibrations from the engine, but that also did not bother us.
Loved our location....we had family members in the cabin to the right of us and to the left was just a crew only accessible area but it had a huge verandah and just had one chair and some plastic tarp blowing around on it. It obviously was not used on a regular basis, but what a waste of verandah space!!!
MJ