This is a lovely apartment in a great location - walkable to Les Halles and the Louvre and close to Metro and bus routes. There are lots of restaurants and bars within an easy walk and it makes a great base to explore Paris. The host's communication was excellent; check-in and check-out were both easy. Note that you are expected to make an additional security deposit (this is in the listing, but we missed it and it came as a bit of surprise). The Mezzanine bedroom is just a mattress on the floor with a very low ceiling above it - you can see this in the photos, but it's not made that obvious, perhaps.
Overall - a good place to stay and a very comfortable apartment.