Silverseas Canada shore excursions

I will be taking the Silverseas Whisper in October from Montreal to New York. I would like to know the best recommendations for shore experiences in the different ports. Are the ship's shore excursions valuable or would we be better off getting a taxi with a guide, van, etc. to show us the different cities? What would you consider to be "must do" in Quebec City, Saguenay, Charlottetown, Sydney, Halifax, St. John, Portland???

Welcome to Cruise Critic.

Let me recommend that you post this on the Silversea board since you are asking about excursions that they offer.

http://boards.cruisecritic.com/forumdisplay.php?s=&daysprune=-1&f=183

If you have questions about the ports themselves another nice place to post them would be the Canada Ports Of Call Board.

http://boards.cruisecritic.com/forumdisplay.php?s=&daysprune=-1&f=39

Keith