I stayed here for a little over 2 weeks after already being in Vienna for 3 months (so I knew the city already). I don't think there are many places better to explore the city from than this one, as it is close to the train/U-Bahn station Praterstern and close to a lot of shops and restaurants. The center is only a maximum of 15 minutes away and as that subway line crosses almost all other lines, it is very easy to get anywhere in the city.
The street in front of the apartment building is quite busy, but nothing of that can be heard inside the apartment; it is very quiet all day and night. The utilities are good as well, with a large and comfortable bed, a nice shower and a useful kitchen with a coffee machine, which was a big plus for me. The price might seem much, but considering with how many persons you can stay here, the state of the apartment and the location in Vienna, I would say it is more than worth it.