This apartment is situated in a typical Parisian building with narrow staircase and no elevator. Prepare to carry your luggage 5 floors, to the top floor. You will have a nice view over the rooftops though. And enjoy the sun and a blue sky on nice days.
The apartment has everything you need for both a short and long stay. Bedroom, living room (with sofa bed), bathroom and a well equipped kitchen. I stayed for just over a month and had everything I needed.
Regarding transport you are within 5-8 minutes of walking distance to metro lines 1, 6, 8, 9 and a RER at Nation. Very convenient location in a local Parisian neighborhood. Close by you have several types of supermarkets with flexible opening hours. You can also easily walk to Bastille in ~15 minutes.
Whenever I had a question, Mercedes was accessible by a message. I would definitely stay here again.