Great location, in front of Wien Mitte station from where you can go wherever you want in Vienna (even the airport/bus station) and it is within walking distance from the city's center.
The flat is one of the best Airbnb I have ever been in: Clean and tidy, with all amenities (bathroom, kitchen, etc.) and Janos (Lea's father) is very kind and helpful. Don't waste your time searching elsewhere: this is a great place to stay in Vienna and I highly recommend it.