Karima's apartment is incredibly conveniently located - literally around the corner from the Saint Chapelle metro station, one stop away from Montmartre, and a mere 10 minute walk from the Gare du Nord. The district itself is a little rough looking, but no less safe than anywhere else in the city.
The rooms are simple but accommodating, with comfortable beds, accessible storage spaces, and provided bedding and towels. The kitchen has everything you need to cook, and there is a fair amount of shared space in the refrigerator. Having 1.5 bathrooms is a lifesaver for a shared space, and we rarely had to wait for access to the shower or washing machine.
Would highly recommend for an affordable leisurely visit to Paris!