The flat is in a very good location. it has three metro stations walking distance, many restaurants, bars and bakeries around it, you can walk to all the main Museums, to Opera, Tuilleries and many other points of interest. There are supermarkets and shops nearby
There was a big inconvenience, though: when I got there, the elevator wasn't working, and I just learned about this fact when I got there, in the spot.
I had to climb six floors of stairs with all my luggage and a ten year old. Nobody told me in advance. If any of us had a disability or a health condition, we would have to move somewhere else.
Two days later the elevator was fixed, it worked for two days and then it broke again. and it remains broken. You must ask them very clearly whether the elevator is working or not in case you want to avoid surprises. I think they should have been more clear on this matter beforehand.
The apartment was very clean when we got there, its cosy, pleasant and it has a beautiful view of the Sacre-Couer. it is slightly smaller than it looks on the pictures.