This is a wonderful apartment! The bedrooms are huge. The AC works well [extremely important!]. It is well-appointed. Beds are comfy. It's two flights up, but there is an elevator.
Our hosts were extremely responsive and friendly!
The apartment was build in the early 1800's. The walls are very thick, and, since it predates indoor plumbing, the bathroom must have been an update. The kitchen and bathroom work well. Has a microwave, which means you don't have to heat up the whole kitchen to get hot water for tea etc.
The apartment is a short walk from the Metro [and it's the end of the line, so you almost always get a seat!]. From there, you can get anywhere in the city. There's a grocery store at the Metro terminal, so you can always pick up a couple of things on the way home.
It's also less than a block from the train that takes you to Pompeii and Herculaneum.
The neighborhood has shops, street vendors, and quite nice cafes for pastries and coffee. I must also mention this restaurant: Ristorante Avellinese. It's a short walk away, serves good food, has indoor seating with very good AC, and the prices are [no exaggeration] half of what we paid elsewhere [order the lemon dolce for dessert!].
There is some street noise at night, but it really didn't bother us.
I would definitely stay here again!