We've never met Stefan in real person but the communication with him via Airbnb was good. The key procedure went via his grandfather, who lives around the corner.
We've spent two nights in the loft and it feels really like luxury when you're in it. The whole building and interior is just new and the loft is spacious. Just bring your own coffee cups to be sure you can enjoy the coffee machine.
The bed is placed at the end of the living room, instead of 'the cave'. I think it's better that way otherwise you could bump your head when standing up in the morning.
We walked to the endpoint of the U-bahn, it is a sportive walk of maximum 20 minutes.
We would recommend this luxury loft when you want to visit Vienna and after that you want to relax.