We stayed at Louise's place in January 2020 (2 adults, 3 kids). Louise was super responsive in her communication, which I would say was the most positive part of our stay. The location of the apartment is great - it's right in the Marais and close to lots of shops, cafes and restaurants. There is a MonoP around the corner which was super convenient for us, and there is a subway stop about 3 minutes away. Check-in was self-service and Louise provided clear instructions ahead of our arrival in Paris. The beds were comfortable, and the Internet was fast.
The apartment itself was a little bit of a letdown. With 2 bedrooms and a living room, there was definitely enough space for our family but as others have pointed out, there is very little natural light in the apartment. There are no windows in the bedrooms and there is only a small 'skylight' and a window that looks onto a small 5'x5' outdoor space. The apartment itself is pretty spartan - there isn't much charm or character. The entire place is tiled, which might be OK in the summer, but in the winter, the floors were cold and actually kind of dirty. When we entered the apartment, we took off our shoes so I know we did not track in any dirt, but our socks and feet were super dirty from walking around the apartment. I would highly recommend the host consider area rugs to add to the comfort for the guests. Also, there is no real dining table - there is a small counter but that's about it. The furnishings are pretty minimal, which is fine, but the black stools in the apartment were in bad shape. The stairs leading up to the first floor (what we would consider second floor in North America) were steep and narrow, so I would not recommend this place for anyone with mobility issues.
Overall, we had a good stay, but I will definitely not be staying here again.