@slothrop Having been to Vienna, I strongly second this.
The metro trains run every 5 minutes or better, and likewise trams. They're incredibly punctual.
And no, Americans reading this, that's not a typo.
Almost every destination you'll want to see is either near a metro station or a tram stop.
Belvedere palace? Tram stop. Schonbrunn palace? Metro. St Stephen's Cathedral/Stephensplatz? Metro. Museum district? Metro.
Many parts of the city centre have been pedestrianised.
But aside from all that, especially if you're from the US, Venna almost certainly has better public transport than your hometown.
And I think part of the Vienna experience is being in a city with world-class public transport.