Positives: A quiet place. A few short steps to a metro stop. Easy self check-in. And you are in Paris!
Negatives: Apartment layout did not offer privacy (we are 2 parents with 2 college-age children). We got interrupted if someone needed to wash their hands or brush teeth. Sleeper sofa had no sheet. No curtains on window for the sofa sleeper. The toilet looked like it hadn't been cleaned. No space in the refrigerator for us as it was full of his opened containers. There were clothes in the washer/dryer, so we could not use. No idea whose clothes they were. WiFi came and went a few times. (We didn't come to Paris to hang out in the apartment, so all we did was sleep there. The issues were tolerable for a short stay.)