We have stayed in the Paris center apartment in the late April for 4 nights. We enjoyed our stay really much as the apartment is in the perfect location. We can go directly to the CDG airport by RER B at the Port Royal station (which has the elevator, very good for us with the big luggage) and do not have to change to any stations at all. Apart from that, we loved to use Paris bus, which enable us to see the Paris street view, unlike metro, which are very convenient from the apartment location. Many bus lines within short walking distance can take us to various places. i.e. Champ Elysee, Opera, Lourve, Orsay, Gare de l'est., etc.

P.S. sorry again for making the accident on the doorknob and hope to see you again when we visit Paris for the next time