I think you'll find differing opinions on this. We had seen Salzburg several years ago on the Ultimate Alps tour but wanted to go back so we arrived in Prague 2 days early and hired a car/driver and guide for a full day trip to Cesky Krumlov. Then on tour we chose the Salzburg option.
In my opinion, CK was better- the tour of the castle which is the main focus there is better than the one of Salzburg's Hohensalzburg Fortress. In Salzburg it is the churches, Mozart, and the city in general. Salzburg is a much bigger town (city) and has more restaurants and shopping, however, if that is what you are interested in. (FYI we used the same approach to touring old town Prague and the Prague Jewish quarter). We worked with PragueWalker for the CK and Jewish quarter tours.
Comments
In my opinion, CK was better- the tour of the castle which is the main focus there is better than the one of Salzburg's Hohensalzburg Fortress. In Salzburg it is the churches, Mozart, and the city in general. Salzburg is a much bigger town (city) and has more restaurants and shopping, however, if that is what you are interested in. (FYI we used the same approach to touring old town Prague and the Prague Jewish quarter). We worked with PragueWalker for the CK and Jewish quarter tours.
OR