This apartment is in the best location in Paris, IMO, right near cafes and shops. The nearest train station is one of the largest with many train lines running from it. It is one stop from gare du nord if you arrive by Eurostar.
The front door to the building is extremely heavy, so some people of a frailer nature may struggle to open it. The apartment itself is nice and clean, with windows you can open yet keep shuttered for privacy and a nice breeze.
It’s a little bit small if there are 4 of you and the couch is configured as a bed, but this is not really a problem. The bathroom has a quite large floor space. I would say that if you were overweight you may have trouble getting into the shower. The gap is about 40 - 50cm wide, not a problem for most but a problem for some.
Sebastian was in touch a lot to check we were ok and answer any questions.