It's a very nicely decorated, clean, and functional apartment, with superb location (very close to a metro station with access to two lines, plus many attractions are within walking distance). There are tons of restaurants, bars, and cafes nearby. As mentioned by other guests, the apartment is amazingly quiet.
The apartment is in a charming old building, with small yet useful lifts. (It really helps to watch the check-in video in advance), as there were more than one lift, each leading to a different part of the building.
The Merveil group is highly professional, sending out information in advance and checking with the status in real time. My questions were answered promptly and we didn't encounter problems with the apartment during our stay.