Natan is a great host. Very helpful, very accommodating and considerate. He speaks English well, which is essential if your French isn't that good. I came to really like the apartment. It's in a great area, and it's quiet. You can sleep well and get a lot of work done, if necessary. There's enough hot water for a nice shower. And the new thermostat provides sufficient heat. Since I stayed during the winter, this mattered to me.
This is definitely a good space for one or two people. More than that might be a little uncomfortable only because it's difficult to get suitcases up the stairs. If you manage to get your luggage upstairs and unpack there's plenty of storage space in the bedroom.
If you like to ride the Metro, the closest stops are about 10 minutes walking. Unless you're in a rush, no problem. Paris is a great city to discover on foot. Often I walked late in the evening and felt quite safe. During the day you'll be tempted by a lot of boutiques and art galleries. Not bad. Not bad at all.