Decision made

Thanks for all the lovely and encouraging comments, my dears :-) I'll respond later.
For the time being, I just wanted to let you know that I've decided to go back to Vienna, stay there, and take my chances.
The decision to go back was well-thought-out and taken for very good reasons, which are still valid.
Besides, if I'm really unhappy in the new position, I can always ask the HR department to transfer me to another department -- maybe I'll have to wait a few months, but I'll survive. I am also woman enough to refuse working too much overtime, if I don't want to. And in the end, living a few years in Vienna and enjoying friends and family will probably compensate for work-related frustration, should there be any.
Feeling much better now.
And I can still go to visit duniazade, so there ;-)