First, the good. We expected a very small place given the description as "cozy" but it was a good size. Very comfortable for two people, not a couple, travelling together. The apartment is very well located in Le Marais. Walking distance to three metro stations. Somewhat of a mini Chinatown with many Asian restaurants, bakeries and green grocers on the street and nearby. Also many French, Italian and other restaurants in the area. It was very quiet with no noise from the streets or neighbours. Both the main bed and the day bed were very comfortable for sleeping. The place has a lot of natural daylight from numerous skylights.
Room for improvement. The bathtub has mold in it. There were ants in the kitchen which we were told is normal in hot weather but it was really just warm and a couple of ant traps would go a long way. The coffee maker had not been cleaned - it had a filter with used grounds and coffee in it. The kitchen is very poorly equipped. There is a cutting board but no knife, scissors, bottle opener, etc. It was nice to have a fridge and some cutlery for takeout but otherwise, not functional as a kitchen. It would also be nice to have a little laundry soap for the washing machine.
In summary, we would probably try another place in the area before staying here again. If it was cleaner and better equipped, it would be a great spot.