We enjoyed staying at Mila's place. It was clean, efficient and well located. It is an approximately 8 minute walk from Gare du Nord, and about a 5 minute walk to La Poissonnière metro station.
The instructions provided on how to enter her place, before we arrived, were precise; we had absolutely no problem walking into her place. It is ground-level apartment and its bedroom is a flight of stairs down below street level. The way the apartment is configured, with its ground floor having a window to below, gives it an air of openness. The only caveat would be that if someone arrived with a backpack, bringing this down below would not be a problem; someone with suitcases, as was our situation, has to master going down an almost narrow flight of stairs with the bag either in front of you or behind (a minor situation that is not within Mila's control).
Mila is very accommodating. Though we never got to meet her, she was always a text or phone call away. There was a small problem with their shower and when this was mentioned to her, she immediately remedied the situation. As a previous guest mentioned, when we asked for extra towels, it was taken care of right away.