I stayed three days at Dorothea's place during my just completed first trip to Vienna and was very satisfied.
The place was very easy to find with the directions she gave me and the apartment close to public transportation and then just a few stops from one of the popular and lively areas in the Vienna center. The room itself was nice, clean and spacious, and Dorothea - though I only had a chance to talk with her a few times - very friendly and helpful.