We really enjoyed staying in Iris's apartment. Iris was very helpful and booking was straightforward. The apartment was extremely cosy in spite of having windows on three sides. It was quiet and very comfortable.
The location was excellent - although it is not in the centre of Vienna, it only takes about 20 mins or so to get to the centre by public transport as the transport system in Vienna is so efficient (we never had to wait more than 5 mins for a bus or a train!). There is also a very good supermarket just around the corner from the apartment, together with other local shopping.
Vienna itself was wonderful. We were there early in January and so were still able to admire the beautiful Christmas lights.