This is not a question, but as travellers want to know how to stay connected whilst visiting a city, I am posting this.
We are two New Zealanders in Vienna for ten days and we both have unlocked phones. For us it's all about the data. Calls and SMS are not as important.
On our first day here, I called into an Orange shop on Mariahilfer Strasse, and got no joy: too expensive and didn't seem to comprehend what I wanted.
By chance I then called into BE- MOBILE at Kaiserstrasse 5 which is near the Westbahnhof train station.
I explained what I wanted, and the energetic man there said "1000 minutes calling, 1000 texts, and 1000 MB for 15 Euro". I handed both phones over and 5 minutes later I am walking out with the new sim cards inserted and everything tested and working!
I was impressed. The network it is using is Vectone. In our time here, the connection speed has been good.
Hope this helps future travellers to Vienna.