After two visits to Paris, we can attest to the fact that location and ease of travel is a huge priority. This apartment is in the perfect location to connect quickly and easily with just about anything in the city. The metro elevator on St. Xavier was extremely helpful, and having the RER B directly from the airport, as well as the M4 and numerous other lines so close was an incredible blessing. We even took huge advantage of the busses that left from St. Michael.
The apartment itself was perfect for our family of 2 adults and 2 smaller children (5 and 11). Our kids slept on the pull out sofa without complaint, and we adults found the queen/double bed surprisingly comfortable. Paris hotels and apartments can be naturally on the small side, but regardless, we found this one to be efficient in space and storage.
The amenities in the apartment were perfectly adequate. We didnt do any cooking, but had everything we needed for our little at-home picnics and petit dejeuners. The boulangerie one block away was very helpful in supplying our morning bread :). The laundry was tiny but useful (bring your own detergent pods), and the shower was excellent. Our host provided the very basics as far as soap, so for a 9 day stay for a family of 4, we just made a quick trip to the Monoprix and bought some super great smelling hand soap. We'd brought our own shampoo and body wash.
This apartment is on a VERY lively street. We loved the energy, and the convenient snack and souvenir shops. It can stay a little loud late into the night, especially on weekends, but we're city people, and with closed windows (we were here in very early spring) the noise was a non-issue. There's one flight of stairs, and then a 2 person elevator after that. We found that very convenient, especially with luggage, though it required quite a few trips :).
The apartment had very good wi-fi, which we find essential for daily planning, but know that it had a tendency to drop at about 10pm each evening for about 30 mins. No big deal.
Overall, we would choose this apartment again in a heartbeat. The location, size, and cleanliness were perfect for our family. I highly recommend it!