The studio is really nice with a beautiful view over Paris. Nevertheless the location isn't hyper-center, the location is good, near 1st main line of metro, so you can go everywhere very easily. The district is safe. I was a little bit late, but the host welcomed us and explained everything.
The only negative side for me was that the bathroom was next to studio but what is main it was in isolated place.
Briefly, my stay was pretty nice and I really recommend this place.