Pauline's flat is the absolute best location in Paris. You walk out and can see Hotel DeVille and Notre Dame - amazing!!! Also you are directly next to a metro station and in la Marais. The location is incredible and worth a lot.
For whatever reason, while we were there, despite lovely weather outside, the flat was very humid (and I'm from Florida, so that's saying something). We reached out but got no response. In fact, we got very little communication overall, which was too bad. We also were provided only 2 already in-use rolls of toilet paper when we arrived. The dampness caused a moldy/urine smell, and the flat lends itself to very little ventilation to resolve this. Also, the beds are pretty hard, particularly the one in the outer loft (there is another loft behind a door in a bedroom). The couch was too wet to sleep on as an alternative (and also has a metal bar in the middle). I'm usually pretty content and love to live like a local, but our group was a bit disappointed in the comfort level. I'd wake up with my legs hanging off the little bed and I'm 5'2" - it was really rough to watch my 6'5" husband try to make do.
So the real question - would I stay there again ... 50/50. That location is truly incredible. But even with a full day of walking to exhaust me I was still waking up in the night unable to rest well. I'd probably avoid hot months?
Or, it could all be solved with two memory foam toppers, 4 pillows, and a dehumidifier. Then this place would be Paris' gem!!
Two bathrooms were nice to have, the kitchen area was convenient. We felt safe. The location was unbeatable!
Thank you, Pauline!