Great experience. Very central flat. Close to the train station. Very close to the heart of old Naples. Close to the boat pier for Capri.
The apartment itself was clean and big. Quiet. Had an elevator, which is not a given in Naples (works with 5 cents coins, which the host provides you with).
Dario and his father were very sweet and helpful. They gave us a little gift when we left.
The only potential negative was that the apartment was a bit dark and stuffy, and that the terrace was dirty (we didn't step out there because our 2.5 year-old would have touched everything).
Absolutely would recommend!