Awesome, fantastic, cute little place, with a beautiful view of the canal and the city. Not in the city center, but that is not a problem, as the 5min walk from the closest metro station are across the canal, with an amazing view as well!
Marlies is a very friendly host, willing to help with any questions you might have, very responsive and thoughtful.
When again in Vienna, this is the place I'm going to check for availability first, for sure!