Luca's place is a perfect hideaway in the historic center of Naples : really quiet (it's on the back side, you can hear only the birds from time to time) well furnished and spacious (a family of 4 will be at ease, with the kids having their own space) and close to everything from the utilitarian (the metro and the taxis are 3 to 5 min away, there are several supermarkets nearby, at least one excellent restaurant and many cafés) to the touristic sites (honestly, I didn't even use the metro, I walked my way through most of the places).
Be aware though that it's on the 4th floor, and that there's a paying elevator. Only the kids room had A/C at the time of my staying, but fans were provided in the other ones. The landlord seems to be willing to add an A/C in the master bedroom though, so you need to inquire about that.
All in all I enjoyed my stay there and I can't recommend this place enough.