I spent 2 months in the apartment and had a very good experience. The flat is wonderfully designed, the location is great: walking distance to Belvedere, quick tram trip to Opera and City Center. The area around is calm and residential, with little things to do, but with such a proximity of the center you don't need much. Airport is easily reachable by SBahn.
Michael is very helpful and always responded fast on all the inquires. I highly recommend the apartment