Fabrizio is a very service-oriented host: great communication, lightening-fast reactions to any issues, thoughtful little touches.
I was only there for two nights, but I found it well-located, right above Chiaia - with its buzzing nightlife, shops and restaurants. 15 minutes from the subway station. (Although if you have knee trouble, you should be aware that it's a lot of steps down to and then back up from Chiaia :) The house is beautiful and furnished with really solid, quality furniture. My room had a massive walk-in cupboard, and the bathroom was lovely (and I didn't even have to share it as I was the only person staying there).
My only criticism, and it's totally subjective, is that for my taste the bed is *way* too soft. Good linen and everything, but if your back needs some support at night, it's the wrong bed for you. Also, it would be nice to have a window... but maybe I'm spoiled :)
Overall I can highly recommend this place, and Fabrizio is the best host you could ask for.