I've stayed in this apartment for about three weeks. In general: very good.
Communication: biggest plus. Domenico responds quickly to questions and is very flexible. He'll think along and he is happy to help. Polite and nice.
Sleeping: the couch doesn't look comfortable, but is actually quite good. No complaints. The bed is easily foldable, which will create a (relatively) large space.
Cooking and generally living in the apartment: the kitchen is small and preparing food takes a bit of creativity, but it works. After a long day, just eat on the balcony (eating in the kitchen is not really an option) and enjoy the view on the square. Do keep in mind that the square is quite noisy in the early morning. I haven't had much trouble with it (I was tired enough after walking around the city all day). The place is equipped with plenty of things (bluetooth speaker, quick wifi, a fan, clothes drying rack, you name it).
Location: very central. Although it seems far away from the centre of Milan, there is a bus and metro nearby and within 20 mins you're in the centre. The neighbourhood itself is also a good place to stay and has good restaurants and plenty of shops nearby.