let's start with the positive: the location is great! However the rest of the experience was underwhelming or even bad.
The bed downstairs was terrible. It was broken and therefore it was impossible to sleep well. Adding to the negative experience was the penetrating moldy smell (the bedroom is in a basement, requiring constant noisy ventilation and a dehumidifier, but this was clearly not enough to prevent the smell).
Less essential but still disappointing was the communication. In stead of welcoming us to Paris it was a long lost of all the stuff we shouldn't do. This impersonal approach was also visible in the apartment itself, which had a sterile atmosphere (even though the space is beautiful).
Without the smell and the bad bed the apartment would be a functional place at a good location. But now it was simply bad