I have mixed feelings about this place. The location - both the position in the city and the actual location of the flat - is pretty unique and very convenient. Also, I needed to cancel the reservation for two nights on very short notice and Klaus did that right away, no questions asked.
However, the apartment leaves a lot to be desired when considering the money asked. The forniture is of the cheapest IKEA quality, and lots of tools and facilities you would expect to find are not there, e.g. a washing machine (I am sure the listing is accurate, but who checks whether the washing machine is there, really?). The kitchen is barely equipped, if you plan a drink or a meal with more than 5 people, expect to bring extra glasses, cutlery and plates.
Do not book this place if you have small (< 6-7 year) kids, as the windows are seriously dangerous (very low, and without any protection).
Do not book this place in full summer season. As the outside temperature rises above 28 C, the place becomes a furnace.
I guess younger people would appreciate the glamorous location, and overlook the defects. For families, you may be able to find better value for your money.