We stayed here with our two teenage daughters for four days, including Bastille Day.
The apartment could not be better located. The Luxembourg Gardens are a block away and we went everyday (and had champagne in the gardens on our last evening)!! We walked to the Eiffel Tower, Notre Dame, the Arc de Triomphe, and the Louvre (all were within 2 miles). There are tons of restaurants and cafes, including a FABULOUS bakery which we got delicious croissants and eclairs at everyday. The RER is about a block or so away, too, and so it was super easy to get to the airport. Melanie met us at the apartment and was very nice. She gave us the key and some minor instructions.
The apartment is also very clean and bright and airy. It's small, which we expected, but the tall ceilings and white paint made it feel more open. There's a washer AND dryer which really helped us, too. There is a view of the other rooftops and of a lovely courtyard from windows in the kitchen, living room, and downstairs bedroom.
There's also Wi-Fi which my teenagers loved.
Some things to consider:
I think it would be hard for *some* people to manage the six flights of stairs up and down the apartment. There is no elevator.
The room downstairs with the two twin mattresses was nice and spacious, but my husband and I were nervous at first about how low and tight the ceiling was over the loft "bedroom" where we stayed. We knew it would be small based on the pictures, but when we saw it in person we both gulped a bit. I'm 5'8 and 140 pounds and my husband is 6' and 230 pounds and we had to climb up into it, however once we squeezed into the space, we found the mattress very comfortable and had no trouble sleeping. But, if you have to get up to use the bathroom in the night a lot or are claustrophobic, it could be difficult to manage.
There were two fans supplied (yay!) and we opened the windows so even though the temperature was in the 80s, it was still manageable (and no apts in France seem to have AC anyway!).
We also thought we'd cook more in the apartment, but there were no cooking knives or cutting board. The plates were absolutely adorable, though. And there were wine glasses, which of course you need in Paris.
The bathroom has a nice and deep, but somewhat narrow tub; there is no shower although you can sit in the tub and use the showerhead. We actually kind of enjoyed taking a bath. But the first night my daughter tried to stand and shower and got water everywhere (there is no shower curtain). So, if you need to stand and shower, this would be a problem.
In sum, this is a good, clean, convenient apartment that is well-priced but it does have some features to bear in mind as you compare it with other possibilities.