Andrei's house is exactly what it's shown to be! We only stayed 2 nights but loved it. Very comfortable and the cleanest apartment I've stayed in so far. Such a treat! The A/C was very welcome given the heatwave and parking in the same building was a huge bonus.
The location is lovely too. You're right by the river where there seems to be a lot of activity in the evening but takes you away from some of the overtly touristy happenings in the heart of Vienna (which is less than 2km away and only 1 train stop away).
We'd come back and stay! And if you're reading this, we'd recommend you to stay :)