Hello, I've been posting in the Czech Republic and General Europe forums, but thought I would also post here for the Austrian bias.
I'm transiting from Budapest to Prague on either Mar 30 or 31, and deciding between plane and train. If train, then I'd like to break up the trip, more likely with a 4-6 hour look-around-town than an overnight. (The sleeper train is surprisingly expensive for a single--much more than a hotel.)
I was thinking of a stop in either Bratislava or Brno, but it feels weird to not see one of Europe's great cities on the way. I know Vienna demands a few days, but between logistics and the concentration of sights, can Vienna be sampled in 4-6 hours? (I'm not opposed to an overnight, but would prefer to just be on my way to Prague at night.)
I don't need to tour any sights; just want get a flavor of the city for a potential return trip. I've heard it's very quiet on Sunday, so that could play a role.