Location, location, location! and View, view, view!!! I don't think either can be beat if you are looking for a place to stay in Paris. Despite being right in the heart of things, the apartment itself is very quiet, and very clean. The beds are comfortable, and having access to full kitchen facilities can be a plus.
Etienne-Marie is a great host, responding super fast to email or messages. He is both charming and interesting, and knows a lot about the local history which he enjoys sharing. He really wanted to make sure I had the best experience in Paris, and I did. When I left, he even walked me to the Metro station and made sure I got on the right train. It wasn't necessary, but it was really thoughtful. If you are looking for a comfortable place to stay in a fabulous location in Paris, you need look no further.