From beginning to end, our experience with Mario was absolutely perfect. We had great communication regarding the location and check-in, and throughout our visit. Mario took care of anything we needed, and the building guardian Gianni provided immediate response.
Now for the apartment - it's amazing. It's right on Piazza San Domenico in the historical center of the City. It is a corner apartment with a view in one direction of the Piazza and obelisk, and spaccanapoli on the other side - providing great walking access to nearly everything you will want to see and do in Napoli. We had coffee and breakfast to the sounds of street musicians playing traditional Italian music - it was like a scene from a movie!
The building is 18th Century with high ceilings and tall french doors with massive original wooden shutters, all of which added to the charm of the experience. It's also very spacious with two separate sitting areas. A modern lift was added to the courtyard, so moving luggage was easy.
At check-out Gianni stored our luggage for a small fee, then not only called a taxi, but escorted it through the pedestrian-only piazza right up to our door - which helped immensely because we over-packed.
I would highly recommend Mario's place to anyone, and would definitely stay there again on our next trip to Napoli.