I don't know what else to say but wow! We stayed at four different AirBnBs during a 16 day stay in the UK and France and this was by far our favorite one. The location is incredible. You can't beat it. There are three little restaurants right below the apartment, as well as multiple restaurants very close by. There are also two amazing boulangeries within short walking distance. The walk to a well connected metro station is only a five minute walk and there is a grocery store only a couple minutes away as well. It's also only a short walk to the Panthéon, and the Quai de Montebello, where you can board a Seine river cruise.
The flat itself is excellent. Be aware that there is no elevator in the building, and it is an old building, so the stairs are fairly narrow and uneven. However, we did not find it to be an issue. It isn't that many floors up, and we stayed in a flat in Lyon which had far narrower and uneven stairs. The apartment is well supplied and furnished. There are great window coverings for keeping the sun out during hot days, and beautiful big windows for letting some cooking air in at night.
Being in a very busy area, it can be quite loud at night, as there are literally three restaurants right below the windows, and they are all open past midnight. However, if you close the windows, you hear almost nothing. We slept amazingly well there, even on a night when it had been 28⁰ during the day. The apartment has multiple fans that keep it quite comfortable.
The laundry is in a shared utility room, but all of the flats in the building are for AirBnB, and we never had any issues using the machines. They work great.
Honestly, this was our favorite AirBnB of the many we've stayed at. We were very sad to leave. If we find ourselves in Paris again, we will absolutely stay here again.