Stayed for a month.
The apartment feels large, clean and is fully funtional in a quiet neighbourhood. Very warm in the winter. Neighbours were mostly quit, though some sounds come through a few times a day.
It is an old building, though, so expect it to have the quirks that old buildings have.
Large supermarket and access to Prospect park around 700 meters away and small convenience stores and the like are close by. Short walk to the metro; it took me around 40 minutes to get to my job in the southern part of Manhattan.
Very friendly host, who was fast to respond and seemed interested in problem solving (e.g. when I arrived late at night with no communication; when I got back online, it was clear that she'd also tried actively to resolve my problem from her end).
Generally a good experience.