The apartment is very clean and comfortable, moreover the host SIlvia was always available and quickly answered to all the messages we sent. It's perfect if you plan to visit Vienna as it is at 5 mins-distance from the subway.
As it is clear from the available pictures, there are 5 sleeping accomodations but there is only one bathroom (this gives rise to obvious problems if you are 5 like we were, for instance you need to carefully manage the hot water for showering).
In conclusion, I highly recommend this apartment if you plan to visit Vienna!