Gerda's flat is in perfect location. Very easy to reach from airport, either by public transportation or by taxi. Check-in was very easy and effortless. She provided all the information we needed and the restaurants/cafes recommendation was great! Vienna was quite hot when we visited so we almost headed back after lunch everyday for a short rest and the location made this very easy. You can have nice walks in the neighborhood at night and there're a lot to see and we felt quite safe.