Our stay at Bernhard's flat in Vienna was very pleasant. We never met Bernhard, but we exchanged messages on our check-in day snd check-out day. The instructions to his flat was very clear and thorough, hence we never really needed to meet.
The flat was very clean and simple. There is minimal furniture. It was a nice stay for us because we were there for only 4 days and mainly used it as a place to stay and sleep. The flat is about 2 blocks from Westbahnof station. Once we figured out the train and bus routes, it was very convenient. We walked to the inner city a couple times, but be prepared for a 20 minute brisk walk. We would suggest using the train if you didn't want to walk such a long distance.
Overall, a very nice place to stay if you are looking for a place in Vienna and are fairly independent on your travels/vacation.