Both Andreas and Liliana were very helpful and accommodating. It was straightforward collecting the keys, Liliana explained how everything in the flat worked and even offered that we keep our luggage at the house on our final day in Vienna until the time of our flight. This was a great relief and allowed us to really enjoy all of our time in the city.
The flat itself was well presented, maintained and equipped and SUPER clean. The flat was always warm, water was always hot, we could do laundry, towels and linen were provided so it felt very comfortable and homey.
Really great travel links, a bike dock, a tram stop and an underground are literally across the road from the flat and the train station is just a 5 minute walk away. There is a Billa (supermarket) on the same street, and loads of fantastic cafes and restaurants in very close proximity. Also lots of interesting shops, cinemas, jazz and comedy clubs a couple of streets away so if you speak German you would probably get a lot out of them :)
The only "issue" with the flat would be step access appears unavoidable, this did not effect us in our stay at all but if you have any mobility difficulties it might be something to consider.

Thoroughly recommend and will visit again soon! (hopefully!)