Had a fantastic stay at Sylvia's. Super-nice and responsive host; she even accommodated our early arrival, which was very nice. Excellent location, in the center of old Vienna. Nice kitchen, if want to cook a simple meal you will have everything to do it.
One thing that future visitors may need to be aware of: The flat is on the second (third?) floor with two very intense and long spiral staircases. It was ok for us, but I would not recommend it to people with limited mobility.
Other than that, the stay was perfect. The host helped with every little detail during our stay.
Thank you, Sylvia.