Vienna is pretty and expensive. As far as cities that look like museums, you'd be better off in Prague. HOWEVS: I suppose with a kid the Opera is out, but at least pass by. Beautiful! There's a museum there that's housed in a palace and it's a little boring (And pricey), but worth it just to see the grounds (Free!). I forget what it's called. Go see the home of the Sacertorte, but don't buy any. It's expensive and mass produced at this point. The window display is cute, though.
In short: Wander, but save your coin.
