Fantastic apartment, well situated, close the metro station (actually 2 metro stations if you are willing to walk a bit to the other line). Very clean - which is important at least for me, a lot of utensils in the kitchen - again for me is very useful, a small coffee machine and everything else. Not very big, but exactly what we needed.
Not sure if it is described in the listing but people with restricted mobility might find it hard / not possible to climb in the bed - the bed is high and you need to climb a ladder (like those twin beds but beneath it is a nice armchair and lamp so that I could read or learn during the evenings). We really loved this arrangement, but just so that everybody is aware.
Myself I will surely return, as I have one extra and important reason now to travel more often to Vienna and the place is exactly what I'm looking for this kind of trips.