Roberto's flat was great. He welcomed us warmly, explained everything in the flat and was very quick at responding when we had a brief wifi glitch. There was also bread, milk, meat, jam, and water in the fridge for us.
The apartment is well set up and it was very handy to have a washing machine. With the windows closed it is very quiet and didn't get too hot inside. We didn't need the aircon on (but if we did need it, it was a very quiet one).
The location is outside of the main tourist/restaurant areas but it's close to the metro line that stops at all the tourist spots. It is also handy to the main train station (20 min walk with suitcases). It's a 15/20 min walk to the colosseum.