I strongly recommend Stephan's apartment to everyone visiting Vienna! I stayed there with my 3 year old daughter for a couple of months. The apartment is super clean and very cozy. It is extremely well-equipped with Nespresso machine and necessary kitchen utensils. It is located in close proximity to the city center (two stops by U4 subway) and Danube Island (two stops by U6 subway). Not to mention that it is only two streets from the Danube canal and a beautiful Augarten park. There are plenty of restaurants nearby and a vibrant market is just around the corner!