We had a lovely stay at Gulio and Margherita's apartment. The bedrooms are very spacious and air-conditioned, and we loved the fact that we also had a lovely spacious living room where to rest after a long day of sightseeing.
Margherita was very friendly, she even managed to prepare the apartment for us for check-in before the scheduled time, since we arrived earlier. She was also available whenever we needed her.
I would recommend the apartment 100% since it is very comfortable, easily reachable by metro, close to amenities and major sights like the coliseum.