Our stay in Le Marais was lovely. The apartment is well located, safe, quiet, and comfortable. Yohann was kind enough to let us check in an hour early - which with the rain and our luggage was super helpful. There was a great assortment of food and shopping close by, easy access to two metro stations, close to the river, and a quick walk or metro ride to most areas of interest.
A few things that we would improve:
(1) there was only one set of keys, which meant that if one person in our group of 3 needed to return, we all had to go back to the place together and leave that person somewhat trapped in the apartment as a key to the gate is required to exit.
(2) We had a few maintenance issues: flashing lights in the kitchen (which wasn't a huge deal, we just kept them off) and a shower head that wouldn't stay up in a tight squeeze stall, which was a big issue throughout our stay as 3 folks tried to shower in the only stand up shower.
All in all, we would recommend and return!