I have been living in these apartments for a month. Marc was very responsive for every question and trouble.
Regarding positives: amazing location, you can get to the Arc of Triumph in 5-10 minutes. The room has everything you need for a short stay, well-equipped kitchen + microwave and coffee machine, a cupboard, a little workzone. This place is perfect for a touristic trip, if you don't plan to stay all day in the apartments. All the necessities were provided, with some extra things like cooking oil and toilet paper on top. That was very nice and appreciated. Internet was fast and reliable.
Regarding negatives: lack of elevator and personal toilet. 7th floor is very hard to reach especially if with the luggage. Also there were troubles with heating, several times a heating battery went off. But Marc has fixed it for me each time. Also to keep in mind, the audibility is pretty high - you can usually hear your neighbors.
Overall I am satisfied with my experience here. Thank you, Marc!