I only stayed overnight en route to a morning flight out of Milan. I arrived at the apartment at about 11pm and left by 6am.
The apartment is a short walk from the Milano Centrale train station, easily under 10 minutes even dragging a suitcase. It's also on the side of the station where the shuttle buses to Malpensa Airport leave from. So, if you're planning on taking one of those, you're in the perfect location. (NB- There are multiple shuttle bus companies and they all line up in a row. Basically, any time you show up you should be able to get a bus, even without buying in advance.)
Despite being a little late, Nic was still waiting outside for me. He brought me up to his place (elevator) and showed me around, offered me some water, and was super friendly. A great way to come to a new city. The room itself has a desk, single size bed, and a fan, which is awesome for hot summer nights. You also have your own bathroom, but not en suite. It's no big deal though, just out the door and through the kitchen, so you're not bumping into anyone at night.
Would definitely recommend for anyone coming through Milano Centrale or Malpensa.