The NCL Sun is scheduled for a refurbishment in May 2016. Some parts are showing their heavy usage. The floor in the Sports Bar (a great place to bring the buffet food and eat in relative peace) is worn, scarred and haggard for example. But, in general, the ship is attractive and functional.
Our inside cabin was great, having a sitting area and plenty of closet and drawer space for two travelers. The shower, however, with its curtain, and tiny circular arrangement was disappointing. On newer NCL ships (like the Jewel), the shower is larger with a glass door.
We were on the 10th deck, Aft, and approximately under the Moderno restaurant and an entrance to the pool. I attempted to get to a lower deck (for noise concerns) quite a bit after I made the initial reservation (and seeing the location because I was on an earlier cruise on this ship). But deck 10 cabin 0122 was almost always quiet with only a couple episodes of loud noises coming from above which was, I believe, crew work. I wouldn't hesitate to have the same cabin again.
Generally quiet. Excellent space with plenty of storage. Shower is tiny with a curtain. TV needs to be updated but not a major concern. Cooling was fine but a bit noisy.
Slow embarkation seemed fast compared to snail's pace disembarkation.