We just left Juliette's quinessential Paris flat in St. Germain after 5 nights for our 5-person family and had a wonderful time there. We would not hesitate to stay there again or recommend it to travelers. I also thought a tremendous value.
Of the many positives, I'll highlight the host's communication, the location in the 6th, and the large space Juliette always texted back within minutes even from Greece. She let us check in early after a redeye, and also spent time calling the cable company to deal with down WiFi. The location was tremendous - only 5 minutes walk from the Seine, 10 from the Louvre, and 20 from the Tuilieries. Rue de Baci just 2 minutes away is a nonstop party and has shops like Amarono gelato, yum yum yum! On space, our family of 5 got to spread out in rooms and the apartment, which helped us relax late in the day. Very quiet apartment too even though it is 2 blocks from the action.
A few things to expect that could be improved but we were fine with: The floors are pretty squeaky, there is 1 BR, and the kitchen is down the hall from the dining room. If you expect these, then come and have fun!