We had a great time at Claudius stay. The apartment fits perfectly 3 couples. It was clean, warm and cozy. Very close to Vienna central Station and Belvedere Palace. We even found minutes away a nice restaurant that produces their own beer called Salm Bräu ( weizen beer was amazing and the ribs and pork knuckle).
We did most of the attractions by foot even the weather was cold like 1 degree but Vienna is amazing.
Claudius was a great host and i recommend to stay at his place