Nice place, great location in wonderful area close to lots of amazing sights. Paris was having an unusual heat wave (was 97°F one day!) The flat doesn't have air-conditioning so it was pretty unpleasant even with the owners provided cooling fans which were definitely needed, used and appreciated. The owner provides a heavy duvet cover which we definitely couldn't use in the heat so we slept with nothing on the bed. Honestly it would have been absolutely fine if it would have been in the 70s low 80s!
I was a bit concerned about noise level at first but with the windows shut and blinds down we could barely hear any street noise, however once again in the heat we needed the airflow. With the windows open there's street noise in the morning that definitely can be heard... I gargabe trucks.
Despite the temperature in Paris and having no air-conditioning we had a wonderful time and did enjoy the flat. The matress was comfortable the shower was hot and fantastic. The flat is smaller than it appears in the photos but it was large enough for us.
I would definitely stay there again if it wasn't going to be so hot in Paris. Would also definitely stay there again in the spring or fall with our son. It's a perfect setup for 3 people (couple plus 1 child) I probably would not expect anyone to comfortablely sleep in the living room on the couch... it's a small couch you can't lie flat on, but it might not bother a small teenager too much.