We had a great time in Vienna and we recommend our stay in Chris' place.
The appartment was great and contained everything we needed (and more!). With it's central location you can get around really fast; The downside to this would be the city noise (can take some time to adjust to sleep if you are not used to it).
Chris was a wonderful host who allowed us to be flexible on the arrival/departure times and gave us some good tips when we arrived.