The apartment is an interior design lover's dream. The Metro station is very close (2 minutes from the apartment). Super close to the Sacré-Cœur area and within walking distance from major train and metro stations. Superb service from nearby boulangerie Chez Meunier. We really enjoyed our stay in the apartment itself.
On the other hand, the area felt quite unsafe, especially in the evenings on smaller corner streets. We've seen a live police manhunt at around 22:00 when returning by foot through Goutte d'Or. On a regular evening, some odd people always stood around the streets. Living in Denmark, it felt very different but we also walked a lot of different arrondissements in Paris and never quite seen anything like this.
I think we would come back though. Next time I would just avoid smaller streets in the evenings and all is well :)