We had a wonderful time in Vienna at Christian's. The appartment is quite rustic, situated in a little building where other poeple are either living or just staying like us for a few nights. The beds are in a little mezzanine, and the toilets are on the corridor. Christian is totally reachable any time you need, as he is working in the building during the day. There are trams and metro to go to the city center just around the building (20min), and all facilities needed, supermarkets, etc.. We were very pleased to stay there for a few nights !