Spent three nights at Kass' place. The apartment is very small (a one-room studio with an alcove set aside for a fridge, sink, & cooking facilities) but this was clearly described in the listing so it wasn't a surprise. The apartment itself was quiet, no noise from the neighbours. And the location is amazing! Everything is right on the doorstep, or within easy walking distance.
Kass was a lovely host: great communication, and flexible with check-in and check-out (which I really appreciated). Would definitely stay here again next time I'm in Paris.