Perfect location, phillipe and julie answer very fast and help with everything, couldnt ask for more from them.
The apartment is authentic and intimate me and my girlfriend stayed there for a whole week and it was great couldn't ask for more.
The apartment is basically in the center of the center of the center of paris, would move it even 1 meter for a better location, 2 min walk from metro infinite bars, resturants, cafes, and shops, the area is not even so expensive.
The only con is that there are many stairs to get there (i assume something like 40)
But besides that i highly recommend.