This flat is in a great, quiet location. It's positioned right on Île St. Louis. My two main Metro stops were Pont Marie and Hôtel de Ville.
This is a small apartment suitable for one person. It has a surprising amount of storage space, a washer/dryer, heated towel rack in the WC, reliable wifi, and Antoine is a jolly fellow and lovely, responsive host.
A light was out in the shower when I checked in, and the management company had someone come out within a few days to fix it.
This flat is five flights up, with no elevator in the building.
The mattress is firm and low to the ground.
There are AMPLE power sockets as well as two USB ports in the wall to charge devices without adapters (iPhone, kindle, etc).
There's a shop around the corner for staples you'll need like salt, pepper, sugar, Nespresso pods, laundry detergent, dishwasher detergent, hand soap, etc.
I recommend Le Saint-Regis for late night wine sips, La Ferme Saint-Aubin for stocking the mini fridge with comté and cheesecake, and La Cuisine Paris, just across the Seine, for cooking classes in English. As well, on the other side of the Seine, and also walking distance, is La Maison D'Isabelle, home of 2018's best croissant in Paris.