My husband, brother, and I stayed in Astrid's flat. It truly was the perfect location for us to see the Paris sites. We were less than a 10 minute walk from the Louvre. About a 15-20 minute walk from Notre Dame. We even walked to the Eiffel Tower one day in about 45 minutes. The St. Germain neighborhood was very beautiful, clean, and had a lot to do.
The flat itself was nice. My husband and I slept on the pull-out couch, which was very comfortable, and my brother slept in the loft. The kitchen was well-equipped and we did use the oven once. I would say it is perfect for up to 3 people.
Astrid had really great communication. She responded to my messages in a very timely manner, let us check-in early, and even stayed to let us in when we arrived earlier even though it made her late for work.
I would absolutely recommend this place to anyone who wishes to see the main Paris sites. Thanks Astrid!