Me and my girlfriend Anna stayed 5 days in November 2014 in this apartment.
The apartment is well positioned, as the metro station is nearby (2 minutes walk) while you can walk near the Basilica of the Sacred Heart in just 10 minutes.
No security issues, there are two access codes + a key to enter.
No problems with noise as the apartment is in an area inside the building and the only neighbor is the family of Lucile (port side).
The reception is excellent: there is also an instruction sheet useful for any need ("the sacred guide!"), For example, I followed the advice for the best supermarket and bakery; in any case you can contact Lucile which is always very polite and friendly.
The equipment of the apartment is complete with everything, but watch out for the Italians: missing the coffee pot for a good espresso! (here in France might not exist!)
Ultimately per apartment and Lucile: promotion with honors, all perfect, is the ideal base for a pleasant stay in Paris.