Mario's place is a nice, clean, stylish apartment which has basically everything you may need. It is located in a nice neighbourhood although not in the city center, but it is 20 min walk to Porta Nuova and 2-3 min with a bus which you may take from a nearby bus stop. There are also supermarkets and cafeterias/bars/restaurants in the area which is very convenient. The apartment is spacious and light, it is well decorated and is fully equipped (I especially enjoyed the kitchen and its equipment). There's also a nice little terrace which is very pleasant for your morning coffee. Mario was a great host, very communicative and hospitable and checked if everything was okay during our stay. Check-in and check-out were easy and convenient.
The only downpoint for me was the bed for the third person because it was a campbed which was a bit uncomfortable. Also lack of A/C may be an issue if the weather gets too hot in the summer. But other than that, it's an ideal place for short or long stay and I would certainly recommend it.