A smart, bright, well-equipped apartment extremely convenient for Gare du Nord.
The apartment is only 10 mins walk from Gare du Nord, in the Barbès area. It's a 10-15 minute walk from Sacré-Cœur and an easy travel to the centre of Paris.
Xavier left plenty of instructions and suggestions to give us a head start and the apartment has everything that you need for a peaceful stay. It does have its idiosyncrasies, but they are what you'd expect from a traditional Parisian apartment building and only add to its charm.
Other reviewers have mentioned feeling unsafe in the area. We passed through Barbès-Rochechouart metro station twice in the daytime. The first time we witnessed a woman having her phone stolen (some locals made the man give it back) and also saw a young man in handcuffs being marched off by police, the second time there was a confrontation between a large group of young men and the police that involved pepper spray. Maybe we were unlucky, but we avoided that station from then on and walked from Gare du Nord. As for the area around the apartment, it has a very North African feel, so lots of men on the street, lots of loud voices and socialising, particularly in the evening. I personally found this added to the feel of community, although my daughters felt a little intimidated by the relative lack of women in the streets.
To sum up, I would definitely recommend staying Chez Xavier, and hope to stay there again in the future.