First let me tell you the good part of the story: Justin seems to be a really experienced host, who's renting this room on a constant year round basis. BUT: The downside of this method is defintely the hygiene of the whole place. A dusty private room, a moldy bathroom covered with hair and a dirty toilette is just part of the problem. Obviously no one really cares for the cleanliness of this place. Midnight cooking with a burned smell in the whole apartment as well as loud late movie sessions is another part of the problem. Yes, it's a small apartment, but that's definitely not the problem here.
Williamsburg is a beautiful part of NYC, but I would not recommend staying at this particular place.