That 18 footer was the first boat that I couldn't feel the resistance of hull pushing water out of the way. I felt a good glide and it seemed I was getting more for less compared to other boats.
I'm a big canoe fan too, having built two 20 footers. The first one I just stretched out an 18.5 foot canoe. Designer told me I should increase width as well, but I didn't. It's a fine canoe, 35" across, but my favorite is the really big one, 42 inches across, 15 inch depth. The difference in the amount of cargo you can carry is substantial.