Really enjoyed the cruise and hike on Bannerman. For us, the combination of cruise and hike just seemed a lot more interesting than a cruise alone.
We were there during peak fall foliage so the boat ride offered great views. Our tour guide was excellent, very knowledgeable and clearly passionate about the island and its history. We had a lot of fun seeing the island AND learning the history of the Bannerman family and their business.
There are a lot of steps initially, but it wasn't bad. The terrain on the island is rough - trails are primitive - so I suggest you wear appropriate shoes.