The apartment and location are great. We loved being able to walk around the Marais and you are a few meters from the Metro. Plenty of grocery stores along the street and lots of cafes and bars in the area. Recommended if you are planning to stay out late and enjoy the nightlife.
On the downside, unless they have been resolved, we had two major issues: the wifi didn't work in the bedroom and seemed to slow down to be unusable in the evenings, and the nightlife means it is extremely noisy in the apartment with the windows open. The second would be okay as long as it is not too hot outside, but in warm weather you have to choose between stifling heat, or not being able to sleep due to the noise and lights. Also note that with the windows open wide, everyone walking by has a good view into the bedroom.
There is a ceiling fan and curtains in the bedroom, but no fan and just blinds in the living room with the pull-out couch. If you are light-sensitive and need to use the pull-out bed, you'll want a mask to block out the street lights.