100% recommend the apartment. Very clean, spacious, has a living room and a bedroom. Kitchen is tiny, but for 2 of us was perfect fit. If you're a bigger family you can use table in the living room. Kitchen is well equipped, the only missing piece is probably a microwave oven.
We never used transopt to get to city center - always walking (around 20-25) min one way. Train station is just 50 meters away, but you can't hear the trains, and the apartment is quiet.
Linens and towels were fresh, dishes were clean. We had all the tools we need, very nice surprise was the umbrella in the apartment and two plastic rain coats. They were the life saviers, as it was raining heavily one day.
Fast internet is a big plus. The host was always responsive and helpful, so nothing could harm our great stay in Vienna.