I lived here for a month. The space is perfect for a solo traveler with a beautiful view of the Eiffel Tower. You can literally watch it from the balcony every night or wake up to it in the morning.
The location for me was perfect, as I was near Sacre Cœur, which is a great spot to go watch the sunset and have a bottle of wine, especially if you're on a date. It's close to Pigalle and the famous basketball court, as well as Pink Mama and the incredible speakeasy in the basement.
It's a quiet street and building, so you'll never have an issue with noise. Although sometimes when I was walking home at night, one neighbor a few building down would be playing Hootie & The Blowfish...not sure how I feel about that, lol.
Plenty of great restaurant and bakeries nearby, a wonderful florist around the corner as well as a tailor and a laundromat. Several grocery markets all within a few minute walk as well.
A short ~5 minute walk to multiple metro locations, so you can get to anywhere in the city. I always preferred to ride a bicycle and encourage others to do the same.
Christian was a great host, communicated timely if I needed anything and was a genuine person. Would stay here again.
Oh, and the building has a lift/elevator so you don't have to lug your luggage up flights of stairs. That's a definite bonus.
Neighborhood is very safe.