The flat is spatious and in a good location. It has all things you need, especially when travelling as a family: wasching machine, dishwascher, kitchen, dishes etc.
What should be improved is the cleanliness. The flat was rather dusty and the floors needed better cleaning since our socks got dirty immediately. The dishwasher needed general cleaning since it is visibly dirty and the odour was unpleasant. The sofa and cushions need some refreshment too because they also do not smell fresh at all.
Regarding Felicitas and her support, it was wonderful and she promptly reacted to all inquiries. However, althouhh we were three people, we got towels and bed linen for two, so we had to ask for more and received them mmediately.
All in all, if the things mentione get improved, the flat would be a perfect place to stay in Vienna.