Great apartment, clean and great facilities. Location is good for getting into the central areas of Vienna via the underground. With the kids, we frequently used the public baths and play park next to the apartment.
We did have an issue with the neighbour who was distributed by the lift door noise at 7:30pm (there is a method to close the door silently, which we got wrong the first day). This was a bit of a low point - but frankly out of the hosts control.