Kalouda is friendly, helpful and very responsive. The appartment was very clean and despite some points we enjoyed our stay.
Some of the listing descriptions are not 100% accurate. I would only like to mention two things:
1) the street noise is really loud, since it's a main street. You can't even talk on the phone with the windows open. In summer, it might be a pain. We even had to buy ear-plugs to sleep at night.
2) the neighbourhood is not exactly one of the good ones in Vienna. Definitely not for families and be careful at night. Unfortunately many housless people around there and the drug-recovery/help center is right across the street.