The apartment has a nice, open living-room to lounge around in. The bedroom is good size too. The bathroom is very small, and a bit cluttered as the washing machine is in there. However, the shower was clean, so can't complain. The biggest issue we had was unlocking/ locking the door. The door is extremely hard to unlock.
The location is away from the main touristy areas in Paris. I wouldn't recommend to a young woman traveling alone, as we received many cat-calls and it felt unsafe walking home at night.
The apartment itself, though, felt safe. We did a bit of food prep, and were happy to find that the kitchen was well stocked.
Overall, I think it's a good place to stay if you're traveling with a friend. There is a nice balcony, and a speaker to play music on. My friend and I enjoyed the openness of the living room and the ability to play some music with the balcony doors open.