Absolutely great location. The apartment was extremely close to multiple train stations, which made it very easy to get around the city. We had a slight hiccup at check in, but Aria was prompt to respond and the matter was resolved quickly.
Daca, our contact in the city was friendly and responsive to our questions and was available when we needed something.
As described it can be loud at night if the windows are left open, but once closed we did not hear the street noise. The four flights of stairs were not as bad as we were expecting, but still 4 flights up. To be honest, we spent so much time out in the city that we did not go up and down the stairs frequently so it really was not a problem. I know the description states no air conditioning, so you might want to keep that in mind. There was a heat wave in Paris with temps reaching 100 degrees while were there. Again, clearly stated in the description of the place so something we dealt with. There were fans in the apartment which did help make the heat tolerable. I would highly recommend staying here, and would definitely stay here again the next time we are in Paris.