Not sure who is Andreas but the communication is with the company "welcome2vienna".
Unfortunately, the apartment was super dirty when we checked in, the toilets, the bed, and other stuff were dirty and below the minimum standard. We needed to send photos to proof the dirty stuff, and only then they did send someone to clean the apartment. We weren't at home when the cleaner arrived and she didn't clean the apartment at all. Only later when we were at home, she came again and cleaned that. They apologized a few times and even sent us chocolate the day after.
Besides that, the location is great, a 5mins walk from Mariahilfer street.