Overall a wonderful little place.
As mentioned in description and comments, the main challenge is the noise from people on the very lively public square below. With the window closed, you can hardly hear it. With the window open it‘s pretty intense.
Little traffic noise. Mostly crowds of people.
There is a central air conditioning though, so if it's warm at night and you need quiet, you can close the window and have aircon on. Then it's quite peaceful.
Everything else is great. Amazing location, beautiful old building with elevator.
Beautifully decorated room, clean, functional mini-kitchenette, bath tub, comfortable bed, great communication with Davide, wash machine access, morning sunshine, (narrow) view of the sea. Multiple Guide books in English.
If you want to be smack in the middle of the most lively area of Naples with a high level of comfort, this is it.