This is a solid place! It's in a nice, safe part of Paris, surrounded by tasty bakeries and coffee shops and some fun bars and cafes. 5 minute walk from a metro stop, so very easy to get around from (it takes about 20 minutes to get to the area with the Louvre, Notre Dame, etc.). The apartment itself is well-lit and pretty, and we were never disturbed by noise from neighbors etc. while we were staying there.
The reasons I'm giving 4, rather than 5, stars, are: first, when we arrived on the first day, the apartment smelled strongly of cigarette smoke. (I think this was from the man who cleaned the apartment right before we arrived). However, I should note that the smell went away after we left the windows open for a few hours. Second, the beds and pillows are not the most comfortable or high quality I've ever slept in, though they are entirely serviceable and clean. Finally, the kitchen has one small pan, two small pots, and no cutting knives, and there were no trash bags for the trashcans, so cooking -- while definitely do-able -- wasn't the most seamless.
Despite these minor drawbacks, I enjoyed my stay and would recommend the apartment, particularly if the above points about bedding and cooking aren't too relevant to you/your traveling style.