The apartment is just as nice as the pictures show. It is spacious, clean, and everything works fine.
Guido and Rosario are the perfect hosts. They went beyond what one might expect from hosts regarding helping out. I lost my suitcase between airports. As I don't speak Italian I didn't make myself fully understood by Alitalia. Rosario and Guido then fixed everything for me, they made all the necessary calls, Rosario even waited to meet with Alitalia's driver so my family and I could visit Pompeii. And the luggage waited for me right by my door, all safe.
I will definitely book Guido's home next time I go to Naples.