Elaine - I said Catholic sights not churches but I did misinterpret your statement nevertheless.

While I do appreciate the architecture of the churches in Prague, I would not rank their cathedrals with Europe's best. Also, given that the Czechs are generally agnostic, I'm not sure how elaborate their celebrations are of certain holy days.

Nevertheless, I think Prague is an amazing destination. I second Kampa Park as well as Restaurant David.

Bratislava is an interesting day trip from Vienna, although I don't know much about Catholic sites there. I think it is about 1 hr. each way by train. Beautiful city!