We had a good time at the apartment. It is centrally located and easily accessible by metro and the RER stations (easy for the airport). Note that with any central location comes loud noise. There are good bars and nearby that stay open till late. You will definitely need ear plugs for sleeping if you are a light sleeper. But that is the price you pay for location. Checking in with a lock code was easy although the gate before the stairs does not open easily from the outside. It will open if you try it from the inside - a bit tricky! We realized other residents of the buildings also have difficulty with the gate, not just us.
It will be helpful if heating and cooling instructions are provided along with the check-in instructions. We arrived late and it was not clear how to turn on the heat, but the owner responded quickly and we were saved from freezing :) It will help if there are some dish towels and a dish sponge. We bought our own.
Overall, a pleasant stay. We will return.