We had a very good experience at Francesco's place overall. The building was a bit hard to find but the check in went smoothly and Francesco has been very welcoming. He introduced us to some very nice places and has been very kind all along our stay. The place is well equipped and had all necessary amenities.
The location is quiet central, you can easily walk to all interesting areas in Napoli, and we felt safe in the streets.
Just note that there is no Wi-Fi in the apartment and the neighbors can be noisy.