Marcus was a very nice and friendly host, replying to my messages before the trip, and being there on time for the check-in and the last minute needs and answers/info we needed. Also i was negligent on the first need material like towels (i thought that was a given, but afterwards i think i was the wrong one for this), but Marcus was kind enough to bring us towels the next afternoon without hesitation.
The apartment is as seen in the pictures, it is cozy and quiet. The Favoriten district is not a high-class one, so be aware of that, but we surely never felt threatened either at our stay. Also there is nothing to do around there. I believe that is the reason for the low price of the apartment in comparison to the rest of Vienna. The price is good. So to get to the center, the U-Metro line is about 10 minutes far on foot (we used it all the time), and the tram station about 6-7 minutes (used that from/to the airport). Also there is a supermarket very close, in the next corner. The flat was clean, but felt a bit dusty, probably for being cleaned beforehand and left unoccupied for some time.
I would definitely recommend friendly Marcus and the apartment to anyone searching for a low-cost cozy apartment, and does not care to stay in one of the better districts in Vienna.