We had a wonderful week in Vienna, staying at Kai's place. The location is perfect, just a few minutes from the city centre's heart.
The flat is small but clean and cosy with almost all the necessary equipment. Though, a couple of minor improvements could be made. First, check-in time is from 4 PM, which is quite late. Second, the kitchen equipment is almost perfect but needs three things - wine glasses, teaspoons and cooking trowels.
I highly recommend staying in this place.