The apartment is great! The place is very nice and it is located in central Vienna, so there is no need to get any public transport, as the main attractions can be reached by foot. Public transports are close by too, if needed.
Hermann was very nice and always available. For example, we had to check in in the evening and he organized everything for us to get in at the time we arrived.
I will absolutely book this apartment again if I go back to Vienna!