Very nice little apartment in the heart of Paris. The apartment is small, but well laid out; it accommodated our family of four for a week without feeling cramped. The place is fully stocked with everything you need for a short stay (coffee machine, washer, etc.), all new, and the whole place was spotless. The wifi was fast too.
The location is excellent, on a quiet street in a happening part of town, and only minutes' walk to shops, several metro lines, restaurants, and sights (Notre Dame really is only about 10 minutes away).
We only corresponded with Marie via e-mails and texts (pay attention to her instructions for accessing the apartment!), but communication worked smoothly and when we had a minor technical issue Marie had it fixed immediately.
Overall, this is a fine accommodation option in a pricy city.