We had an wondeful stay at the Foria House. As a party of 8 (4 adults and 4 teenagers), we booked the whole house and therefore saw everything it offers. The house can comfortably accomodate 14 people, each in a comfortable bed. No sofa beds here. The garden is an amazing plus in central Naples and allowed our kids to strech out and play ball after a long day of travelling and visiting Pompeii.
The house is a large appartment with 4 bedrooms, each with its own bathroom and Wifi (!) The common area is large and boasts a modern kitchen with a large fridge, coffee and tea, drinks, etc. There is fresh bread and pastries delivered each morning for breakfast and the whole place is cleaned each day. It was really easy and comfortable to stay there and get going each morning.
The decoration is trendy and cool, and you get a feeling for the younger Naples there. Air con in each room was appreciated too.
The House is located walking distance from the Archeological Museum and the trendy student bars around Piazza Bellini. Cabs are easily available if you want to go across town to the waterfront or other sights. The subway stops by the House too, for a different Naples experience.
The only thing I would say is that you need to book a cab to go to/from the airport (max 30 EUR) because, while it is possible to get the by public transport, the time difference is huge (20min vs. about 1.5 hours).