The apartment is extremely conveniently and centrally located in the popular tourist area. Being in that location, and one with tend to think it would not be quiet, but it is extremely peaceful.
Every amenity that I would have wanted, was offered. Extremely comfortable bed as well as drapes that almost darken the room during daylight (when one arrives with jet-lag).
For those who like to have food at their apartment, a large grocery store is about a six minute walk (Reminder for those from the USA, you do need to purchase and bag your own purchases).
Many of the main tourist sites are walkable or via subway. I would recommend the Vienna card which gives unlimited bus and subway rides. There are also hop on-hop off tour buses. If you haven't looked at this information in advance of your stay, Mark also has several tour books for your use in the apartment.
I highly recommend this place, it is truly a gem!