Saint John was very scenic but I didn't really find much to do. The town is very tourist friendly and geared toward tourism. We walked to the "reversing falls" but you have to get there at low tide to see any real turbulence. If you do go to the falls, make sure you talk to Lynn in the information building. She is extremely knowledgeable about the falls (and the region) and clearly loves talking about it. She'll give you the whole run down on how the water flows, reverses, and why it is called a "falls" when we don't see a waterfall.
After walking back from the falls we went to the shops in the Square but it was just like a mall (nothing I couldn't see at home). The space was well designed and feels open and inviting. All in all it was a quaint little town infused with a little industrial flair. It's a nice day off of the ship but there are other places I'd like to see before going back there.