This Davy knot looks good, but I have always tied flies on using a Duncan loop. First knot I learned at a fly fishing class back when I started. I'm talking multiple decades here and the loop has always served me well. I've used it on small flies to steelhead. I'm curious about knot strength comparisons. I've landed 20 inch browns on size 20 flies (not telling where). Definitely gonna start practicing though.