Stayed for 3 nights in Stefans apartment, enjoyed a long weekend in Vienna. It's super relaxed to check in at the place, so when I came in in the middle of the night to find the apartment, there was no issue in disturbing anyone :) that's a major plus!
Also the apartment is located next to metro Station and surrounded by options for public transport in general, offers affordable grocery shops and restaurants in the area and is a quiet place. It's a simple apartment but Stefan adds everything you need: a cozy bed, a hanger for your clothes, a fully equipped kitchen with all essentials and a bathroom with goodies (shampoo, toilet paper, towels). You don't need to worry about anything and can enjoy your stay in beautiful city of Vienna.
I would recommend this place :)