I am afraid I cant comment on the job situation. Its probably not exactly the European counterpart of Silicon Valley :) but they nonetheless have a fair share of IT companies. Maybe check out http://www.karriere.at/jobs/edv-it-organisation?states%5B0%5...
As for the city, yes it's quite a nice one, good infrastructure, lots of cultural heritage, nice environment and so on .... for the past six years it ranked #1 in Mercer's list of quality of living survey. Though to be fair, last time I was there I do admit I had the impression some things changed and it seems it has become less safe recently. So that might be something to consider as well.