I stayed in Costanza apartment for 10 days with 3 teenagers and my parents, 7 of us. First Costanza was very good in pre arrival communication and even went out of her way to help me when I was I. A tight spot. She welcomed us warmheartly when we arrived, almost like finding a new friend. Have us information about the area. The area is close to stationed Termini which makes it very close to any public transport you need while in Rome. It's great if you want to do day trip out if Rome too. Monti, (one of my favourite area in Rome), is 10-15 minutes walk from the apartment. Restaurent are 5 minutes away and just under the apartment there is a little 'bar', love their fresh spremuta d'arrancio, have a short black at the bar before you day in Rome.
The apartment was very clean and well furnished.