The apartment is clean and the interior is cozy. Even though it's small, we felt pretty comfortable because everything is done with attention to details. There are a lot of restaurants within walking distance, the subway is just 4 minutes away, you can walk to the Louvre within 20 minutes. An additional big bonus is that host allowed us to check out late without a fee.
Cons are: we did not felt very comfortable with entrance (narrow steps and ugly corridor to them, a street full of prostitutes nearby); neighbors can be pretty loud (from stomping from the ones above you to the music at night).
Nonetheless, our overall experience was positive :).