Localization is very good. Everything is in a walking distance: Hauptbahnhof, Stephan Dom, Hofsburg, Museum Quartier, Belvedere. So we didn't have to use any means of transport.
Check-in is very easy - there's a key waiting in the safe box in the same building. So the check-out is even easier - after 7 days you now at last how to open a box (a joke of course).
Apartment is big enough (for a couple) and clean. In kitchen you have everything you need. Wifi works well.
The only disadvantege was a noise caused by some construction works in the building, but of course it is temporarily.