Overall, we loved our stay here. It was my boyfriend's first time abroad and in Paris, and this location/stay was exactly the vibe I was looking for in terms of introducing him to the city.
As described, the apartment is small, but with a lofted bed and very tall ceilings and windows, the room really does feel spacious. For my United States visitors, this apartment is on the second floor, so you do go up one flight of stairs (I know in Europe and other continents the first floor is the floor above the ground). It gets really good natural light, and I'm very happy that there was a small air fan you could set up next to the bed since we were visiting just at the end of summer.
I forgot this in the description when we arrived on a Monday night, but there is definitely an Armenian society downstairs that welcomes you with their singing; it's actually incredibly charming, and they definitely do stop singing by the time you'd like to go to bed. There are two entrances to the alleyway this location is in, and one does have people who sleep outside, but we a) never found them intimidating, b) passed by them early in the morning when the city was asleep and safe, and c) entered by the other end of the alleyway so we could feel "safer."
The bathroom is, as described, 'cosy,' and will fit one person at a time, but when you're traveling with a partner, this is totally fine and manageable.
Overall, the apartment is in a fantastic location in the city; you're close to a handful of Metro stops, walking distance from a Nicolas (affordable wine shop), two franprixs, one Monoprix, some parks, the river, and les Perigots (super delicious french style restaurant). The apartment is basically in la Republique square, and while there's a very lively scene in that area, you don't feel overwhelmed. We found ourselves returning to the apartment at least once in the day to nap and drop off our things from traveling around, and it was very easy to get there and back out to whatever you have planned.
Jenn is a wonderful host and responded to all of our inquiries before our trip. Thank you for a wonderful time!