This apartment is fantastic. The pictures don't do it justice. The space is large and everything you need is provided. My family (2 adults, 4 kids) were completely comfortable staying here for 9 nights. We would stay here again in a heartbeat.
The location is incredibly convenient. It's practically in the shadow of Sacre Coeur and the metro station out front makes almost all the major attractions accessible in 25 minutes or less. There are two grocery stores, a butcher and at least half a dozen bakeries within a few blocks. Not to mention that Gare du Nord is a 10 minute walk away.
The elevated metro line out front does make a bit of noise. We were there in December so the windows were always closed and mostly it just sounded like a gust of wind. Didn't bother us at all.