We really liked to stay at Sonia's place. It's a cool studio apartment which is way bigger than on the photos.
The location is super, ca 20 min walk to the Duomo (metro station is ca 3 min) and the Milano Centrale is only 15 min walk away.
The area has really good restaurants nearby and a park where you can go for a run or walk with your dog (Giardini Pubblici Indro Montanelli).
Please note that the air conditioning is not included and you will have to pay 10€/per day if you want to use it.