I stayed in the Große Schiffgasse 28 apartment for six weeks. The flat is small but entirely practical for one person. The lower level, where the kitchen, bathroom and living area are, is very comfortable and has a lot of light (there's also a balcony with a really good view of the street, which has lots of nice old buildings, and in the distance the Stefansdom). The bedroom is on a mezzanine level, and is a bit featureless but perfectly fine for sleeping. The biggest advantage is the location in the 2nd district: the trendy, up-and-coming Karmelitermarkt area, which has lots of shops and restaurants, is two minutes around the corner. The 1st district is 5-10 minutes by foot. It is also very well-connected with respect to public transport. Alin is a very nice, helpful guy, who went to a big effort to fix the internet when it wasn't working.

Some negatives were, first, that the (shared) washing machine is in the basement; although this is quite normal for Vienna. Second, the walls in the apartments are quite thin so you can often hear the neighbours, although I got used to this quite quickly.

I would definitely recommend the apartment for people staying in Vienna, especially those staying for a longer period of time!