Carla's apartment was perfect.
It is equipped with anything you might need during a vacation. There is an elevator in the building and Carla even leaves you the coins for using it.
Carla was so nice and communicative. We asked for an early check in and she agreed happily. Carmine came over to open the door and show us around. When we didn't know how to operate the coffee machine, Carla came by to show us.
Carla does not speak English but we managed with translation on the phone.
As for the neighborhood - if you really want to feel the vibe of Napoli, this is your place - the dynamic bustling Spanish Quarter is amazing and in a short walk you are in the main street and close to all the attractions. The windows are double glazed but we did hear noise (honking) from outside (it was Christmas weekend so I can't say if this is regular).
Please note, no taxi driver will take you to the exact address (they won't drive in the narrow street) and is about a 10 minute walk uphill with luggage.