We took the light house tour since most everything else was either about Anne of Green Gables or lobster. Lots of driving, little time at each place, not all that great....Didn't really see anything special at PEI which was the one port I thought I'd really like.
Halifax was a wonderful city and the trip to Peggy's Cove was worth the hour drive BUT again we were not given enough time once we were there. I'd suggest finding a tour that gives you 2-3 hrs there if you want to grab a bite to eat and see any of the shops. We were there 1 hr and only had time to walk thru the town and back (with a short bathroom stop).
We did a tour that took us to the top of Cadillac Mt and then a schooner sail. It was wonderful!! And Bar Harbor is such a lovely town - great shopping and be sure to stop in the drugstore to see the ORIGINAL soda fountain (they served delicious homemade ice cream too - try the blueberry)