In a word excellent.
Location - The location is great for the train to, for example, Pompeii, the Royal Palace at Caserta and Sorrento. The location is great for the historic town streets where most tourists go for small shops, bars and restaurants. In addition, it is a couple of minutes walk to L'Antica Pizzeria da Michele - widely accepted as the best pizza in Naples.
Facilities - The apartment is spotlessly clean and has all the essential amenities for home cooking, laundry, entertainment or even working from home. Although we didn't take children I could clearly see the apartment was suitable for young children. Besides a sleeping cot, there was even a small box of toys and table corner protectors.
Security - Like any major city, Naples has its fair share of petty theft. Hauber House has an outside light and very secure doors with "4 dead bolt" locks. I felt extremely safe in the home and had no worries of leaving passports and money at the apartment.
Communication - Antonella is a Super Host for a reason. If you need something she will try to help; if you want to be left alone then she will leave you to enjoy your vacation in peace. The point is, she is there to help you.
I will be recommending Hauber House to my friends and relatives.