Our stay at Dominik's apartment was lovely. It's conveniently located right next to the train station and close to the city centre. There is a metro station right below which takes you to the city centre in about 5min, or to the Schönbrunn Palace in ~20min. You can also take a gentle walk to the city centre in about 25min if you feel like walking.
The apartment is perfect for two couples (in our case we were three people), clean and modern. We'd definitely recommend this to anyone visiting Vienna.