The apartment is fantastic with a great location close to the historical district and train stations. The neighborhood is authentic and lively with a treasure trove of restaurants, pubs and shops, not to mention the museums and Pompeii. The place is even better than the descriptions and other reviews given on AirBnB.
I stayed at Sal's with my wife, son and his friend and we all loved the place and wished we could have stayed longer, unfortunately he was heavily booked (and for good reasons) if you see a few days in his schedule, better jump on the opportunity.
Sal was a great and understanding host. I let my son talk me into using his phone as a wireless hotspot instead of buying a SIM card for my phone while on the trip. Consequently I was very limited in my abilities to communicate with Sal, actually I was terrible about it and he was very patient and understanding (thank you so much Sal!) We got lost and were very late meeting with Sal, when we were able to finally communicate, he helped guide us in, then personally took us to the public parking area and then negotiated a lower rate for us...way beyond any typical host...especially since he was waiting for us outside of his apartment for at least an hour while he dealt with our stupidity.
Sal is extremely knowledgeable about the area and gave us a great introduction before we went out to explore (on foot....driving in the area is not for the weak and naive like us)