Very nice place to stay! Though it is not in the central "arrondissments", the mini-flat is conveniently located near the "Gare du Nord", the metro station is a walking distance, and it is served by some buses and night buses as well.
The apartment has everything you need for a short and comfortable stay.
Gisela is a very nice host, kind and helpful, and communications have been very good before, during and after the stay.