This apartment is a delightful surprise. The building is very old, 16th century, and the stairways and courtyard seem as though they've never been changed since then (except that the courtyard is now a parking lot!) The stairway up to the apartment is old stone, very wide and imposing, scarred in places, and somewhat forbidding. The elevator may be Italy's smallest, but was fine for the two of us.
Then you open the door to the apartment and Voila--it's the 21st century! Whoever decorated the space has a good eye, and the colors and choices are very attractive. We would have preferred either a larger sofa or an extra easy chair, but made the one small one work. Since we are both 75, we probably spend a bit more time resting inside than the average couple (certainly more than we did even 10 years ago.) The kitchen is modern--unfortunately the electronic ignition was broken when we were there, but matches worked fine. The host left some goodies, which were much appreciated.
The location is excellent, especially for walkers. Although the neighborhood is far from posh, it's fine, and everything you need is right outside or a short walk away, including supermarket, umpteen cafes and restaurants (we use Yelp), and best of all--the Archeological Museum, which is right across the street. If we ever come back to Naples, we'll stay here again.
Noise? Although the building is right on a busy street, we didn't hear traffic. But we did hear our neighbors! The windows all open into what we would call airshafts (maybe tiny courtyards) and Italians are loud talkers. I bought some earplugs, but my husband was fine as his hearing is very bad!