My boyfriend and I were in Vienna to visit for few days. We choose Justina's flat because we thought it would be comfy - and we were not deceived. We were welcomed with surprise treats we didn't expected and it was very appreciated. The flat was clean, quite big and felt like home. It smelled good, although it was a little cold (Austria in October!..).
The flat is about 7-10min to the city center by tube, quite close to anything there is to see.
Overall, we had a great time in Vienna and Justina's flat was one of the main reasons why ! I highly recommend it :)