This apartment is perfect for a large group of people (> 5). Has 4 bedrooms with many wardrobes and shelves needed for your clothes. Everything is super clean and fresh (you fell like the apartment was just renovated and refurbished), the bedrooms have large windows and curtains, so it there is lot of light and the bedrooms are spacious.
There is a very fast wifi connection. We stayed in winter and it was also very warm and you could control the temperature from a single control point. Anyway, if someone needs more blankets every bed had those underneath.
The kitchen was not very spacious but we managed to put another table (from the living room) there and could have breakfast there with all of our family :) This is because we visited in the winter and it was too cold in the backyard you can see in the photos to stay there.
Corinna was very helpful and supportive. We have checked in easily, needed tablets for the dishwasher and she has brought those to the apartment the same evening.
The apartment has one bathroom (so you need to build up a schedule for using it in the morning/evening :) ) but 2 WCs, so it makes life a lot easier :)
What I especially liked in this apartment is that it looks and is very fresh, light, has many shelves and wardrobes where you can fit in all of your clothes and it is in the first floor which makes it very easy to access.
You should not bother about its non-central location as tram n.46 will take you there and the stop is just around the corner and it arrives every 10mins. There is a food market a minute of walk away, so you can buy all you need there.
I would say that if you have a big family / group of friends this place is just perfect for staying in Vienna for a few days.