Fantastic location. We liked that the flat was in a more residential neighborhood close to restaurants, bakeries, produce stands, pharmacies, cheese/charcuterie/wine shops, etc. It made it easy for us to grab dinner for takeout, or pick up groceries to bring back to the flat. There were several close pharmacies for getting our Covid test before returning to the US. And every time we left the flat to go sightseeing, the Eiffel Tower was right outside to greet us.
Plenty of room for our family of 5. It was very convenient to have 2 bathrooms as well as the common living and dining areas. We stayed downstairs while the kids stayed in the two upstairs bedrooms. The kitchen was well equipped for takeout, but I probably wouldn't use it for cooking. The laundry appliances in the flat were also a big help so that we didn't have to pack as much and could wash/dry a load while we were out and about.
The concierge services were highly responsive and super helpful. They answered all my questions promptly. They allowed us to check-in an hour earlier so that we didn't have find a place to store our luggage the day we arrived. They arranged a private car for us back to the airport per our request. And they helped us figure out which pharmacies would provide the testing required for our return to the US. I loved having that service despite not staying at a hotel.
The common living area is at street level, so you see people walking by if the curtains are not closed. But all of the bedrooms are located away from the street, so it didn't bother us at all. There were also some noisy neighbors in the building that woke us at 2AM a couple of nights. Not sure if anything can really be done about that, though.
All in all, it was a great place to stay and we would definitely recommend it.