Christophe's place it's just a gem in a little dreamy neighborhood.
In a typical Parisian environment you can access markets, restaurants and stores with food from all over the world.
There are two metro stations very close to the apartment (about 700 meters/0.4 miles) with connections to practically all over Paris. I even went and go from/to the airport (line RER B) for only €11.
The neighborhood is very safe. I went there for work and I came back home every night around 1 am and I never felt unsafe.
Christophe is very quick responding any questions you may have but to be honest I didn't have to contact him more than once and it was for an advice. Everything else is explained in a handbook he leaves at the apartment.
I will be coming back to Christophe's apartment.