Our stay at Jean-Noel's flat was disappointing.
First, the good points: The location is AMAZING, in the heart of the Marais District and with easy access to transit; it's also a fairly large apartment, with two good sized bedrooms and one slightly cramped one; our experience was that, contrary to a previous reviewer, the apartment was clean (though it's old, which can make a place feel dirtier than it is.).
Unfortunately, the experience suffered from a number of small issues that added up to an "okay" experience (at best): The TV and freezer were both broken; the lights in the bathroom flickered in an alarming way; there were very few comforting touches provided (minimal paper goods, incorrect coffee pods for the maker, no toiletries); The registration and check-in process were fussy and complex. Also... there are mice. Each adult in our party saw them at one point or another during our stay. I will admit that mice are a reality in a building of this age, and they were likely stirred up by some construction in the building (which was disclosed.) But I think it's important to mention because for some folks, that's a total dealbreaker.