I agree with some other reviews, they can really do better with the place.
The location is spectacular, all the major attractions in the old town can be easily reached on foot. The flat is actually a studio, no door between the bedroom and sitting room, just a frame, but is roomy for two or three person.
The equipment and service could use some improvements though. I booked the place for three, but it was clearly setup for just two. No extra bedding available in the room. I slept on the sofa with only a bath towel for the first night, because we'd been arrived very late. They brought in the third set of bedding the next day when they received my complaint. Plus the sofa is really just a sofa, not a sofa bed. The cushions "placed" on the sofa cannot be moved, which makes little room for sleeping in, even with me being on a smaller size, less than 160cm/45kg, I don't feel comfortable.
The key box really takes some time for figuring out, if you never saw and used one. I'll say a picture of the box can be helped a lot. It took me a while for realizing those are the key box I was looking for.
They have a full kitchen but little kitchenware, kind of a waste.
One more thing, the flat is on the third floor with narrow stairs, big luggage can be a challenging.
Overall, we still enjoyed our stay, the location certainly overruled its downsides.