Catherine's place was exceptional. It was exactly like the photos, so neat and tidy. Such a gorgeous place. Catherine was very communicative, and so kind and helpful. If you are lucky enough to stay in her amazing apartment, be forewarned that you may not want to leave.
The bed was so comfortable - nice and firm, there were plenty of clean towels, hanging space in the closet, and plugs were easily accessible (something we have not always found). Catherine will give you keys/access information to her place. It is very secure.
Regarding location: it was perfect for those who want to be a part of the city, and still close to things. We could walk to Monmarte. It was about 3 blocks from an underground station. You could see the Eiffel Tower from your room's window.
Note: when you arrive, you will need to contact her through the intercom to activate the VERY tiny elevator. Only one person and one suitcase at a time. This was not an issue, just a surprise.

This is a true gem of a place to stay.