This is a very nice and clean apartment, with three big sleeping rooms, an ample living room, and really quiet. It is located in a safe building near the Rebibbia metro station (5 minutes away on foot). The ride to the Colosseum takes about 20 minutes; we took advantage of the 7-day metro/bus pass which for 24 Euros allows unlimited travel during this time period. Everything was in perfectly working order, with fast WiFi connection. Daniele is a very nice and friendly guy, who made us feel very welcome (he also provided some items for breakfast).
All in all a place we can highly recommend to anyone who wishes to visit Rome.