My stay at Eva Und Michi's apartment was fantastic. I had a delayed flight and Michi graciously waited at the apartment for arrival, even though it was outside the check-in window. They provided me with a very long list of restaurants and sights to see as well, which helped me enjoy Vienna even more.
At one point, the shower drain wasn't working very well. I sent an e-mail to them and got a response within minutes indicating that someone would be coming over immediately to try to fix it. They scheduled a plumber and made sure the problem was fixed very quickly.
The place was clean and spacious. It was also very well-located, just minutes walking to many nice restaurants, the Opera, and Karlsplatz. It's also minutes from a U station which can get you truly anywhere in the city. I will absolutely stay here again when I return to Vienna.