We had a great time staying in Fabio's apartment! Fabio was out of town, but his friend Antonio met us in a nearby piazza and got us oriented to the apartment and city, and was very helpful answering all our questions in fluent English. The apartment is located uphill from Piazza Dante. The balcony looks out over a beautiful, elevated view of the city and Mount Vesuvius. The apartment is a short walk (8-10 minutes) from the metro, and maybe a 15 minute walk downhill to Via Tribunali. The wifi worked great. We felt comfortable using the small kitchen to prepare simple breakfasts. The mattress is a futon mattress and is quite firm, but the apartment was very quiet so we slept fine during our four-night stay.
We would definitely return to Fabio's apartment when we next visit Naples.