Overall, I think this place could be great. The location is nice, the courtyard is nice, the security is adequate, and the space is large. In fact, the owners were very responsive and friendly. However, I think there were many small things that added up to make the place feel unwelcome, or that they didn't bother to prepare for our arrival.
First, I will start with the good. The location is nice. It is about 50m from a metro station and bus station, which makes it easy to get to from both the airport and to travel to sites. The space is large, unlike many spaces in Paris. There was lots of natural light. There are multiple doors with security codes to access the location, meaning the security was also good. Many good cheap eats that are very close.
To us, it felt like someone left the apartment 15 minutes before we arrived. In general, the place didn't feel clean, especially the bathroom. The bathroom around the walls is dirty, and has a bit of a smell. The washing machine was unusable, as the odor coming from it was horrible. I feared my clothes smelling worse after being washed! There was also a significant amount of personal storage in the closets, shelves, etc. Not that offensive, but definitely not mentioned.
Now the bad. The kitchen was probably the biggest turn off, and the reason we felt the place wasn't cleaned. In the fridge, there was a moldy lemon, opened water bottles, a broken chocolate bar...etc. I understand keeping some sauces for guests, but this didn't seem like it was even looked at. And while some may find this next point enjoyable, we felt it offensive. There is a shelf with many open bottles of alcohol; some close to being full, while some 95% empty, both wine and liquor. Enjoy it if you want, we don't know where it came from and made us uncomfortable that it would be left there knowing that someone could have tampered with it.
In addition, due to the bathroom door handle being broken, we got locked in the bathroom for a few minutes! ha!
While we understand that it wasn't the most expensive place in Paris, it could have been better. In its current state, I wouldn't recommend it, but with some small changes it could be great!