I spent 6 months in Roberta's apartment and it was a lovely experience. She is an incredible and really comprehensive host! The apartment itself has everything one might need, even though the space is super tiny.
The only thing I think it's important to point out (and that isn't extremely clear throughout the taken pictures) is that the bedroom is about 1.55m high, so a person taller than that will have some discomfort in longer stays. Also the flat gets really humid due to the lack of windows around the kitchen/bathroom area, and you might experience some noise during the night due to the cleaning of commercial buildings in front of the flat.
Furthermore, I experienced some problems with the water heating system of the apartment when there was more than one person living in the loft, since it basically heated water for one shower and the second person would not be able to take a hot bath. This was really stressful during winter time, since there isn't a proper heating system in the loft (only an air conditioner) and taking cold showers was a big no-no.
And last but not least, if you plan on staying for a long period and plan on cooking your own meals, I recommend you find somewhere else to stay. The kitchen is incredibly tiny and since it's located under the building's stairs, the ceiling is super low, which turns cooking (or even dishwashing) into an extremely hard task.
This all compensates, however, with the AMAZING location of the apartment, which is located in the heart of the Navigli area (with the intense nightlife that comes with it). Public transportation was also really close to the flat, which made moving around super peaceful.
I would definitely recommend the flat for short/medium term stays!