The apt is in a central location. If you put the address on you GPS it will tell you to take the metro and get off at Strasburg Saint-Denis station and walk about 4 min. That route won't look good. But further past the apt is nicer. Walk to Rue Montorgueil and you will see it's a nice area.
It's also a 6 floors walk up. So be ready.
The apt however was not clean. I had to borrow a vacuum cleaner from the lady who was cleaning the apt next door so I could clean a bit myself. There isn't a single soup spoon in the apt and the plates on the cabinet were dirty. Also the heater was off and It took me a while to figure out how to turn it on. Some things are also broken. Like the faucet in the kitchen sink. Yankel was a quick responder and answered all the questions I had.