This is definitely very far from luxury and it is very overpriced. It is a very small ground floor flat of one living room with a sofa bed, which when open occupies almost the entire room. The two bedrooms are also very small with (small) double beds occupying almost the entire room. There is a single small toilet and a separate single small shower room (with a good shower). There is no possibility of 6 people (we were 2 adults and 4 children) eating in the apartment, there is a counter at which 2-3 people can comfortably sit, but 6 cannot and when the 6 chairs provided are placed at the counter you can barely move in the room and you cannot cook or open the fridge because the chairs are in the way. 6 people can cram themselves in and function just about, provided they eat out, but it is very far from luxury. There is no air con, so in a Paris summer windows need to be open - the living room window opens directly (with a frosted security glass to prevent entry) onto a busy Avenue with traffic noise, people talking, smoking etc, the ground floor bedroom windows both open onto the building (shabby) courtyard and anyone could climb in with no obstacle at all, so we had to keep them closed for our children's security, hence no ventilation in stifling heat. The sofa bed is so small that my wife (168cms) had her feet hanging off the end, my (183cms) legs hung over to my knees. It is well equipped and well decorated and the location is indeed lovely, but it is very very overpriced in my view (we paid 339 GBP per night).
Communications with Merveil were terrible with 27 e mails received and 24 texts received (none of the texts had any content beyond the first two words) before I finally received the details needed to enter about 2 hours before entry. I drove to Paris in faith that the details would finally arrive, but was highly anxious that my family would have nowhere to stay. Merveil also asked "if possible" for copies of all 6 passports - since it was an "if possible" request I did not initially provide as I was in the countryside with difficult access to IT. I was then bombarded with texts, e mails and calls insisting on provision of copies, all while I was driving to Paris from the countryside. Also Merveil repeatedly requested that I "fill-up the check-in form" - this form was never sent to me despite me repeatedly saying I had not received it. In the end it was never received and therefore never filled -up. I cannot describe how irritating this process was.
Finally, all the talk about this being "an historic building" is nonsense - it is a shabby run-down building and we had neither sight nor sound of any neighbours, it is also meant to be a non-smoking apartment, but it stank of cigarette smoke, a stink we could not get rid of because there was no ventilation.