My wife and I spent six weeks in Beata/Johannes/Phillip's apartment and it was perfect for the two of us. The apartment is clean, neat and functional with all the small things that come in handy for a long stay (drying rack for clothes, iron, vacuum cleaner, hair dryer). There is also a washing machine available in a laundry room one floor below. Beata was very helpful and always responded immediately to our questions.
The house is just a few minutes' walk from tram/bus stop, so it's easy to move around (Tip for those who stay long: Buy a monthly public transport pass for around €50. This lets you hop between all of Vienna's tram/bus/subway lines with no restrictions).
We enjoyed our stay in this apartment, and we can wholeheartedly recommend it for both short and long stays.