For everyone who wants to feel at home in Vienna: go to Sybille! I stayed with her for three months while I was doing an internship and I had the best time. Sybille is so wonderfull, always in a good mood, speaks very good English and is very welcoming (for example, she would put fresh flowers in my room, bake cake, ...)
The apartment is exactly like the photo's and the location is perfect: close to various bars/restaurant/shops, in a trendy neighbourhood of Vienna and close to the city centre.
The apartment is clean and tidy, even while there live two nice cats. They don't come into your room if you don't want that so you really barely notice the cats are around.
I will definitely go back to Sybille whenever I am in Vienna!