Stay here if it's available. You won't find a more authentic Parisian experience. The view is magic. You can have a coffee in the morning whilst looking at the Eiffel Tower and across hundreds of Parisian rooftops. Then at night, watch it all light up.
The space itself is very clean. Ample room for two, comfortable beds and couches. Small kitchen and laundry facilities. Easily access to metro and local supermarkets and restaurants.