Perfect location - the strict city center is just after crossing a river, around 5 minutes walking. You can easily walk to many main locations in Vienna including museum district within 10-15 minutes without using public transport. There is a metro station nearby so other attractions like Belvedere are also easily accessible.
The place itself is perfectly equipped, amazingly clean and quite spacious. The beds are really comfy. Wifi works without problem. Wolfgang's daughter welcomed us and explained everything. She also gave us keys to the parking gate which is available for free in the courtyard.
It will be my first choice on the next visit to Vienna. Fully recommend!