Alessandra and Fabrizio's apartment puts you right in the heart of Napoli's historic/touristic center; everything you'll need or want to see (and taste) is within easy walking distance. Other things that aren't so close physically (like the islands of Capri or Ischia) aren't hard to reach since the apartment is very close to both the embarkation and disembarkation points for the ferries. Because the metro is 2 or 3 minutes walking away (Toledo station), you can also get to the railway station quickly, and travel to Caserta, Ercolano, etc.
About the apartment itself, it's very spacious, has a wonderful kitchen with well cared for and properly working appliances. The bathroom we had suited our needs perfectly (and each room has its own locking bathroom, so you don't have to worry about sharing with strangers), and the bed and pillows were very comfy. There is a bit of noise from Toledo below, but that's just part of life in Napoli; after a night or two, it grows on you :-).
Alessandra and Fabrizio are great, thoughtful, caring, and kind hosts. Alessandra was always in touch with tips and suggestions, and help for any kind of question we had. Fabrizio was very reliable and friendly; he even picked us up early for our trip back to the airport. They're great people, and perfect ambassadors for their city. Although we didn't ask, I'm sure that they can recommend guides or experts if you're interested in something specific, so you get a real all-in-one package with them. The only question is, what are you waiting for? Book the room (or rooms), you won't be disappointed!