The location of this apartment cannot be beaten. Walking distance to most of the major attractions, and a short tram ride to the ones that aren't.
The apartment is kitted out with everything you need and a supermarket near by is handy for picking up some supplies. There are a lot of restaurants nearby though if you don't feel like cooking.
Stefan was very responsive and his instructions were clear. We knew what to expect every step of the way.
The only small issues are the fact the curtains are not blackout, so if you need darkness to sleep - bring some eye shades.
The room was also pretty hot, and there was no fan for air circulation. Meaning you had to open a window to get any cool air through, but because of the location that ends up being very noisy.
Despite this it was a great apartment and we really enjoyed our time in Vienna.