We had a wonderful 5 night stay at Saint Emilion. The spacious 2 bedroom/2 bathroom flat was perfect for our family of four. The views of the Eiffel Tower from the living room cannot be beat, and we were easily able to access other parts of the city (Louvre, Latin Quarter, Monmarte) using the metro, taxi and just walking. While the building is vintage, the flat has been nicely updated making for a very comfortable stay, including air conditioning, dishwasher, clothes washer/dryer, and nice furnishing/touches. We used the manager's recommended driving service (Victor Cabs), which was reliable/arrived early. We flew in very late, and the manager and driver coordinated to make sure we were able to check in after 1 am.
The only set-back for us was that the elevator was out during our stay, and a 6th floor walk up was not ideal. That said, it is a vintage building, there was little the management team could do to resolve the issue, and we were able to make it work. If you have any mobility issues, you should consider whether you can safely make the walk up/down 6 floors if the elevator is out (which happened at more than one location during our trip due to older buildings/smaller elevators).
Elevator aside, we can easily recommend that anyone staying in Paris rent this flat for their stay -- it will exceed your expectations.