Wonderful trip. Prague was beautiful in every way...wonderful city...great 'old' flavor to it and yet very easy to get around on metro trains and streetcars. All the cities visited were great...but some of the best, in my opinion, were Bratislava, Czeny ***orov , and Kutna Hora. These were fascinating...and the ossurary in Kutna Hora was something very unusual...I have never seen before.
I definitely recommend the extension in Prague to give yourself time to explore and enjoy the city at your own pace and to fit your own tastes. It is worth the extra money.
About the only complaint that I have is the amount of time available to explore on our own...I think this was particularly true in Salzburg which has much to offer but we did not have time to do. For example, I would have liked to go to the fortress...but there simply was not enough time available after lunch before we had to get back to the bus.