Great property, fantastic location in the Marais which is one of the best locations, if not the best location in Paris, as you can walk to everything. Lots of great restaurants within 5 minutes walk. And the shops of the Marais are mainly independent boutiques and bar/catering outlets... the Pompidou Art Gallery and the Picasso Museum are 5 mins walk away. And the Seine and Notre Dame an easy 10 minute walk.
The apartment is very comfortable - nicely designed with 4 bedrooms (but only 2 toilets). It's in a quiet courtyard, and you really don't get Parisian street noise at all. It's got good heating for winter lets. We had 7 of us staying and that worked well. Bedrooms are very small (but typical for Paris) with very limited hanging space. Living space is great for socialising. Good bluetooth speaker included and a decent TV.
Only critique (apart from cost - it is expensive) is that it comes with none of the necessary cleaning products - one bathroom didn't have soap. I'm a fan of AirBnB hosts that provide whatever someone else has left behind as long as it's sanitary - e.g. why repeatedly buy a dish brush for a 2-3 day stay? But apart from that, if you can afford it, it's great and I'd stay there again.