We were 4 persons staying together during our Vienna trip.
The flat is very good overall.
It had a very nice feeling, coziness, cleanliness and minimal design contributed to nice aesthetics.
The decorations were decent and thoughtful.
It has a great shower area.
It has a separate (pretty small) toilet.
The living room and kitchen area is big and comfy and the bed is also big and comfy, no issues with that.
The bedroom was also good in size with a nice bed and wardrobe.
The flat was always warm due to underfloor heating.
The location is okay. If the weather is not kind then you definitely will have to use transportation which was our case for most of the days.
The flat is on the ground floor which was a real convenience for us due to having lots of baggage.
The only issue we encountered was the lack of WiFi in the bedroom due to signal loss.
All in all the flat is good and we recommend it to anyone visiting Vienna.