Vienna was part bus, part walking. We stayed on the outside except we had time to go into the church (not a Sunday). We did get quite a bit of the history and a decent orientation to the city. We stayed in the city and took the metro back to the ship. Our guide gave a good orientation at the end. We went to the Albertina museum on our own. It was a nice mix of half small collection of famous artists and half palace rooms.
Budapest is also part bus, part walking. Good orientation to the city and one of the easier ways to get to see heroes square and castle hill and hear some of the history. The cathedral was crowded since all the tours arrive in the morning.
We went to the hospital in the rocks on our recent cruise. They have tours in English that last about an hour.