In Quebec City do the part day city tour off the ship unless you are a really good walker. You can wear yourself out walking there. Or should I say climbing! Avoid any tours in Halifax that run you out to Peggy's Cove to an overcrowded gift shop. The lighthouse is nice, but not worth the cost and bother. I can't think of what they would offer in Sydney other than a trip to Bedeck and the Graham Museum and a look at the view. A good thing to do in Sydney might just be to have a brief look around and then have a cup of tea! Don't tour in every port. You make a vacation into a job!