First the positives - This is a wonderful space, decently located in Paris. The apartment is enormous and has so much character. Great for larger families and groups. While it does not have A/C, the temperature can be regulated by opening the windows at night and early morning and then closing. However, we did have a lot of street noise one night that made having the windows open less than ideal.
Now the issues - The management company who runs this Airbnb seem to have problems. We confirmed the morning of check in that at 3:00 the apartment would be ready. An hour later we received a message that check in had to be pushed back to 5:00 due to staffing issues. We arrived at the apartment just before 5 to find the cleaning staff on the street unable to access the apartment. We helped them get in and were told that it would take until after 7:00. We were able to leave our luggage at this point. Also be aware that the key needs to be picked up from a convenience store several blocks away. We were only told the evening before about having to drop the key back there upon check out. The store managing the key drop doesn't open until 10:30AM which made this impossible for us as we had an early train booking. You should factor this into your plans as the timing and location can make it tricky with luggage in tow.
The apartment itself needs maintenance and de-cluttering. As mentioned in another review the apartment definitely feels "lived in"...like the owners just left 5 minutes before we arrived. Some people like this, we don't. Combined with the large space you have to be careful to leave your own belongings in a confined area so items don't get missed when leaving. There were also issues with the electrical. Some plugs don't work in various rooms and the lights in one bedroom and some hallways didn't work. We lived with the electrical issues rather than giving access to an electrician (which was offered) while we were out or staying there to oversee. Finally, the pictures present the space as in overall better condition than in actuality.
If you need a large space and go in with realistic expectations this Airbnb might be great for you, but it would not be our first choice for future trips.