I stayed at Massimo's place for 3 nights. The check-in and check-out processes were easy, the apartment was clean, spacious, full of light, and close to the Coliseum. When I say, I mean around 100 meters. The apartment is suitable for up to 6 people, the two bathrooms are modern and work well (the shower in particular is a treat), the beds were big and comfortable. The air conditioning and the fans deliver a perfect temperature, which makes staying inside pleasurable even in the summer months.
Close to the apartment there are many restaurants (I tried La Taverna dei Quaranta and Naumachia, which I both recommend), gelaterie, and coffee shop.
The apartment was fairly priced. I greatly recommend renting Massimo's place for a fantastic visit to the eternal city.