I am actually staying permanently in Vienna, but I needed to book an Airbnb due to some problems that came up with my new apartment.
The apartment of Alviva and Arthur is very nice and clean.. very warm too, especially if you consider the cold in Vienna. Nice decoration and cozy:)
It's really in the centre, in a nice neighborhood and very close to everything! Especially if you are here on vacation, it is an ideal apartment to book if you want to have fast access to all means of transport. Supermarket is very near the apartment too.
The bed is slightly small for two people, but very comfortable!
The communication with the hosts is very good, they respond instantly and give you all the information that you need.
All in all I would book the apartment again if friends and family would come over. :)