I had an excellent stay at Wolfgang's place during my time in Vienna. The apartment itself was incredibly clean, comfortable, and well-decorated. As other reviewers have mentioned, it's very close to the metro, grocery stores, and restaurants. I found the temperature within the apartment to be perfect; not too hot or cold.
There were some minor issues with check-in, but Wolfgang was very friendly and responsive and quickly addressed any issues, and his recommendations for things to do within the city were excellent.
I would highly recommend staying here!