Wonderful location on the fifth floor of a secure building. Thomas met us precisely on time and showed us all the details of the apartment, including how to use the washing machine (which would not be intuitive for an American). The fully-equipped kitchen was a great convenience, and the Nespresso machine was lovely for coffee first thing in the morning. The bathroom had a nice shower and the queen-sized bed was comfortable. Make certain you always have your door key with you as it is a specialty key and you would need to contact Hélène if you lock yourself out. Getting out of the main door is a bit tricky if you don't know how. There is a small button in the door which you press to unlatch the door.
We walked an average of ten miles per day and found the location to be about equidistant from Notre Dame and Montmartre -- and just a few blocks from the canal. Our neighborhood was filled with every kind of shop or restaurant or café one could need. The Tuesday and Friday market on Richard Lenoir was a special treat and the vendors were kind and helpful. Seeing many single women walking alone at night looking at their phones is a good indicator to me that the neighborhood is safe.
All in all, if you are looking to be away from the touristy areas, this is the perfect location to consider. After a couple of days, it felt like home to us.