"Simply perfect!"
Pros: The apartment is located on the 4th floor in the historical building right in front of a very beautiful Votive Church. The room is fully equipped with everything you would need for a short (around one week) stay, including WiFi, Led TV, kitchen, etc. Everything is very high quality. Location is perfect. Plenty of site-seeing places, like Rathaus, University, Parliament, Burggarten, Hofburg Palace are in walking distance. For those that are located relatively far away you can take metro or tram. The station is 5 minutes to walk from the apartment. Easy access to the airport (through U- and S-bahns), bus, and railway stations. There're plenty of cafes and restaurants around but if you prefer to prepare a food by yourself, there is a very good Billa supermarket nearby. The landlord is an extremely nice and helpful person. His office is located on the same floor right in front of the apartment and if there's a problem he is always ready to assist you. It is a very smug little appartment, every detail is perfectly well thought of. It is perfectly calm and could not be better in a luxurious hotel.
Cons: I haven't experienced any.
Summary: The location/ quality/ friendly and helpful landlord vis-a-vis and it's price makes this apartment an absolute winner. I would strongly recommend it to anyone who is planning a visit to Vienna.