I have an Old Town Canadienne Kevlar I picked up used about 8 years ago. It was a mess when I got it. Bondo and burlap patch, mice in the float tank ends and bent and kinked gunwales. I fixed the patch and replaced the gunwales and thwarts with wood. I have been on several trips in the BWCA with it. its pretty heavy due to the wood and patches.
I'm starting to think about something newer. My primary bow paddler is my son who has grown to be larger than me. He will be 200 pounds 6'2" by the end of this summer.
I have paddled a few other canoes. But never back to back with the Canadienne or with similar loads.

I'm wondering if I am going to notice a huge performance gain by getting something more modern.

Thanks

I think the performance difference you will notice most is your own performance on portages. The Old Town Canadienne was not a real light kevlar boat to start with. 58 pounds if my memory serves me right. A new kevlar 17 footer from Northstar, Souris River or Wenonah is going to be in the low 40s.

The Canadienne is probably the swiftest boat of a traditional design. The only people who would notice a lot of paddle performance are folks with real solid technique who could push a more modern hull to its highest performance. If you are a more casual paddler you probably won't notice a whole lot of difference.

I think the Canadienne is a sweet boat for touring, solid in wind and waves. If you don't mind the weight and like the way it feels, stick with it.

My step father owned one for about 30 years. We finally convinced him to move up to a lighter weight model about 5 years ago. He went with the Wenonah Escape, purchased from Piragis at the end of the season. It's a nice ride, a bit tighter in the front end than the MN II, but noticable faster to paddle than the Old Town. The Old Town is a nice stable fishing canoe, but as mentioned above, you'll really appreciate the lighter weight of the newer Kevlar canoes on the portages.

He was pretty excited when he sold it, I think he got ~$1000, roughly the same amount he paid for it in 1985! His was in very good condition.