We have stayed in Alix's spare apartment for three days.
Although there were a lot of disappointments on our trip, Alix and her apartment were not amongst them. Communication was very easy and responsive, and Alix even enabled us to arrive a day earlier on very short notice. She also gave us great suggestions for bakeries and restaurants.
The location of her appartment is unique: it's in a very lively and popular street in the Bastille area with tons of bars and restaurants literally next door. And yet it's suprisingly quiet, because it is open only towards a courtyard.
We especially liked the additional space from the lifting bed and the modern and easy-to-use bathroom.
We had some minor issues too. The wifi is atrocious, probably because there's so many other networks around. Try to join the 5GHz network if you can. The mattress is hardness grade 3, which was a bit too much for us. And because the bedroom is directly adjacent to the wooden staircase, you need to be a heavy sleeper not to wake up from other inhabitants walking up or down.
But these were minor things. If we wanted to revisit the area, we would book here again.