Great little flat near the Invalides and Champ de Mars. Stayed with 3 adults, I wouldn't recommend any more than that, though. We used the laundry facilities, which were very convenient and even had a tumble dryer, something I've never had in any of the other flats I've rented in Europe (indeed, even when i lived there my landlord didn't have one).
Nearest Metro stop was Invalides, which was about a 8 minute walk, and fromt here only one train change to make it all the way to CDG.
Lucie was easy to communicate with via SMS, and met us at the flat on arrival.
One word of caution if you're traveling with a significant amount of luggage, the flat is a 4th floor flat (3rd floor everywhere else), so you're looking at a significant number of winding stairs and there is no lift. Just keep it in mind.
The restaurant, La Poule au Pot on the ground floor was very good, the sushi place Miyako, was just okay. Nearby is a G20 supermache and a couple boulangeries for a morning croissant or pastry.
I'd happily stay here again.