The flat is in a wonderful location, central to all you need, and easy access to the Metro, on a beautiful, lively square. The beds were very comfortable with high quality, crisp linens. Kitchen had very nice appliances and the washer/dryer (and detergents) were most appreciated. The bathroom is large, well-lit and stylish with soaps, etc. supplied. (Note that it is all marble, including the floor, so could get rather slippery if balance is an issue.) Check-in was a breeze and Dennis was consistently responsive, including dropping off extra hangers.
Important aspects to note: the flat is on the first floor of an interior courtyard from the square (not looking out on the square as I mistakenly assumed). This location means that, with the windows open and curtains drawn, you look into a small courtyard that houses cars, bikes and the garbage bins, and anyone in the courtyard would be able to look straight in at eye-level. We were out and about most of the time so I don't know whether there are a lot of people in and out, so during the day this was not an issue for us. When we were in the room during the day (there was one rainstorm that sent us inside a bit early), it felt a little dark and contained. Because of the access, we were not comfortable with leaving the windows open at night so the ventilation in the place wasn't great and could feel very close inside. While in the flat it was helpful to open the back door (which looks into another interior courtyard) but again, we felt uncomfortable leaving it open all night while we slept due to the access available to others in the building. Natural lighting was also an issue due to the need for keeping the (heavy velvet curtains) closed to have privacy. There are a few lamps, which mainly supplied "mood lighting;" no real task lighting. (We are also three tall people so the ceiling felt low to us, but that's likely a personal thing.) There was regular noise in the courtyard at about 5 am due to the restaurant that shares the courtyard dumping bottles into the recycling bin. I slept through it with the aid of earplugs, but it woke my daughter and husband almost every morning. The interior courtyard itself, other than that, is very quiet. There is no storage space (i.e., no closet, dresser or luggage racks) for clothing other than two small moveable hanging racks, meaning we had to leave the majority of our clothes on the floor in suitcases for the week we were there. Surface areas in general are at a minimum, limited to a large coffee table and a dining room table; no side tables next to beds.