The host is very communicative and considerate. It is extremely clean, accommodating & comfortable. I stayed for 2 nights (the last night I went out), and I would definitely recommend only for short stays.
I had a flat mate who invited some friends over and started playing music super at 12am in the morning, whilst also yelling across the flat, and naturally (especially because it's not a real room) I couldn't sleep until they left, it was just far too much noise (which was around 1:30am). Obviously that isn't the hosts fault so I don't blame him at all.
Overall great experience, if I go back to Milan, I'd definitely stay here again.