We spent three days at Vienna. The apartment is as described...clean, nice and comfort. The house has the elevator.
The location is very good, the U-bahn is a few meters away, from where you can reach all the destinations.
There are free parking spaces (during weekends) just on the other side of the street, which was perfect for us.
The app is perfect if you come to Vienna for a concert (at Stadthalle), because the location is only a few stations away.