I stayed in Gianluca's apartment for a little less than a month, and overall enjoyed my stay. Communication with Gianluca was excellent, and the location of the apartment is perfect. The space was comfortable for two people, though the second bedroom is extremely small. The kitchen is new and perfectly functional, though the bathroom could use a little sprucing up. The apartment is on the third floor, up a very steep staircase, which might be a challenge for those not used to climbing stairs. It's also directly across a narrow street from a police station; the street is narrow enough that the proximity to the police offices can sometimes feel a bit uncomfortable! In general, though, the front room is fairly large and comfortable. Of course there are plenty of amenities in the neighborhood, and you're extremely close to the centro storico.
Overall I thought this was a decent option in the neighborhood, with the location and easy communication the best aspects of it.
One tip: there is a shuttle bus from the airport (SIT shuttle) that has a stop on via Crescenzio, a short walk from the apartment. For 7 euro it's the cheapest and easiest option to get to the apartment from Fiumicino.