Don't trust Maps on your phone for the house number - trust the house numbers hanging along the street, you would need the number 4.
What I liked: there is a wi-fi, the place feels spacious, we were greeted, shown everything we needed. The place is very central, there is a metro and a rather big supermarket open till late nearby. Though, in a nice weather, you may not even need the metro. The biggest impression is the building itself: it is quite old, and the doors look very unusual. I was surprised then in the Museo del Prado by quite similar doors everywhere - from the same epoch, I assume. Loredana even offered each of us a set of keys.
Small nuances: the bathroom door is rather low - I am 180 and managed to hit it while was distracted. And the water is heated by the boiler. So if you are two and need to wash your hair - better to wait for a couple of minutes between each person taking the shower.
Overall - quite a nice flat to see the downtown.