My husband and I enjoyed our stay here.
The room was in a wonderful location. Easily walkable to the Louvre, Notre Dame, St. Chapelle and near the metro for whatever is further away, or if you just can't walk any farther. Both Silvia and her boyfriend Maël were very nice and easygoing. Maël sat down with us when we first arrived to point out areas on the map and make suggestions for bakeries and restaurants, which was very helpful and appreciated.
The wifi worked great. The only possibly negative thing might be the fact that another rental room is located directly below this room, which could be a problem if your neighbors are noisy. We heard our neighbors' Skype conversations each night, though they did this at a decent time and we were never too bothered by it. The bathroom is also shared, but the toilet and sink/shower are separate, which makes it a bit easier. We never had a problem.
The bed was a bit firm in my opinion, but my husband liked it quite well. Silvia and Maël were also kind enough to allow us to leave our bags for a short time after check-out to see some last minute sights before our train left. We only had carry-on backpacks, so traveling up the stairs to the apartment wasn't a problem for us.