I had a great time in Vienna staying in this appartment. It is spacious, and has been very recently refurbished, all the equipment is new, the washing machine is also a dryer, and there is a dishwasher. It was perfectly clean. In a high floor of the building, it was quiet; I rarely heard some distant noises from other appartments, I was never disturbed. Heating is adequate (it was winter).
Location is fantastic: on the north side of the historical center, it's not in the middle of tourist action so it quieter than a few streets further. There are 2 subway stations with 3 lines 5mn away, and a tramway stop 2mn away. It's direct from Hauptbahnhof and Wien Mitte (where you catch the train to the airport). Although the center of Vienna is easily walkable, it was great to have all these public transportations available in winter. I went many times to the opera; it's a 20mn walk or 10mn with the subway. There is a nice supermarket right across the street, and the great Merkur Hoher Markt is 3 blocks away.
Jonny was very flexible with check-in and check-out times, that was much appreciated! Everything went smoothly. I highly recommend this appartment.