I really like this place. It is a 15 minute walk to the Vienna International Centre where my meetings were being held, so the location is convenient. It is also on a quiet street that borders a lake and has a park at one end. I was able to swim and go jogging after work.
That being said, I would try to avoid rooms 2 and 4, as they are close together and share an outdoor area. During my stay there were rather noisy occupants of the opposite room that also spent a lot of time sitting in the outdoor area just outside my window smoking and talking. They were not behaving inappropriately, but I found their presence annoying. I have stayed here before in a different room where this was not at all a problem, so I would recommend avoiding rooms 2 or 4 if you think you might find this bothersome.