This is an excelent place to stay, super clean rooms with wonderful room service. Very comfortable beds and nice lounge area on the ground floor.
A little bit further away from the city centre (walking 30 min or taxi/uber 15 min), but literary 2 min away from the famous Prater fun park. Surpassingly you can't hear a thing if you have your windows shut.
We will definitely stay again when visiting Vienna.