Spent 2 nights there. Didn't see anyone of the owners or the hosts or Celine but had no worries at all because the instructions was very clear and easy to access the apartment.
The place was very very clean, full equipped, probably renovated, new furniture.
Location was good, near 2-3 stations but we went to Le Marais by foot both days (about 15' mins) and its near Republique.
Totally recommended, good price, especially for the expensive Paris.