The apartment is very central to Sacre Coeur/Montmartre area, which we loved! It is nicely decorated.
We had some trouble with appliances (the hot water tank leaked, the washing machine was hit or miss if it would work) and the unit is older, doesn't breathe, so the humidity was high and the windows fogged up easily). Armelle was easy to get ahold of, and responded well to the issues. The precise street of the apartment is pretty lively, although we didn't have any issues, even on the days where we didn't get home until 10pm.
Overall, nice place - with a bit of attention to the appliances and better ventilation, I would definitely stay here again.