My personal experience is I've been fine, Dominik is very nice and attentive and he helped me throughout,
he received me on arrival and departure, to explain everything and to help me with my baggage, although I already had an assistant, thanks Dominik anyway !! ;) so these days was very warm in Vienna, he left me a new fan in front of my room without asking to him anything. Well, the flat is large and there're more rooms, but you don't have any problem because there're two WC and a part two extra showers, plus the kitchen. the apartment is very well located, you have two undergrounds stops from two different lines a few meters and airport transfers also good. Ok!!! I personally would recommend this opcion to spend a few nice days exploring this magnificent city. You won't regret it!!!