Emeline's apartment was good for our 4 day stay in Paris. It consisted of a clean bathroom with shower, a short hallway, 1 room (that contained the kitchen & couch that converted to the bed) & a small balcony with bistro table & 2 chairs. The apartment is easy to find if you follow google maps.
Good points: the place was clean & more spacious than we expected. Kitchen was kitted with everything we needed for making romantic dinners. 1 of the best markets in the city takes place Tues/Fri/Sun 100metres from the flat @ Place des Fetes (7am-2pm). It is on the 1st floor of a very secure apartment block. There is very little noise. Emeline stayed in the apartment next to us while we were there. There are great value gastronomic bistros serving highend food & wine at low prices within 400m (Le Baratin/Chapeau Melon/Quedubon). Rue de Belleville is full of great bakeries, cheese shops, butchers & more. Even Chinese acupuncture clinics giving 1 hour pedicure&foot massage for €30.
Bad points: Belleville is a rough & ready neighborhood with a large Asian/black/Indian community. Fine if you want the real Paris but not what you might want on a romantic trip to the city of lights. No velib bikes at any stations in the area on any day during our stay. We couldn't get a bike until we hit the Canal after a 40 min walk. Also, it is located at the top of the steepest hill in the city - so if you plan to walk or cycle, you might rethink that & take the Metro. It is too far from the centre to come back to during the day for a rest. The sofa bed isn't the most comfortable - sleep with your head towards the kitchen & feet towards the window for the best sleep.
The apartment is good value @ €50 per night & it is nice to have a balcony to sit sipping wine in the evening. Just be aware of the steep hill & the distance from the centre. Apartment only sleeps 2 on the convertible sofa.
Your best bet is to be out all day in the city & come back to make a relaxing dinner enjoying it on the balcony. Alternatively have dinner locally at 1 of the restaurants I mentioned above so you have a short walk home.