Giusy's apartment is a great option to stay in a central area of Milan. The building is old, but the studio itself and the furniture are new. The kitchen is well-equipped, which is not necessarily the case in other places. As to the location, it's near Porta Venezia, which is a nice neighborhood with restaurants, bars, supermarkets, and bakeries. It's not that far to walk to the Duomo region if you're not in a rush :)
As to Giusy, she was very helpful and nice from the start!
The only downside of the building is there is no sound isolation. The street is normally calm, but during weekends you might hear a bit of the movement there.