Josh -- in the "official" tests I've seen and in my own experience (both basement and stream testing), any line > line knot will almost universally be weaker than a tippet > fly knot. The uni-to-uni, blood, surgeons of various turns, J-knot, etc. test somewhere in the 60% or so breaking strain limit of the lighter material versus the higher strength you generally get with *most tippet > fly knots. The non-slip loop is a
very strong knot, so it would be an anomaly for someone fishing a hand-tied leader to have breakage at the loop knot versus the first knot "upstream" of that. I dunno?
A bimini may be an exception to that -- but most folks don't attach tippet that way. I suppose using a tippet ring would remedy it as well, but I hate those things.
Cary -- I've heard people advocate loop knots for dries (in addition to the typical streamer use), and the argument makes sense. I use a Duncan loop more than any other knot, so the choice of whether to leave a small loop or cinch to the hook eye is as easy as it gets...you slide it down another few centimeters or you don't ;). What I've noticed is that after catching fish (or debris) which causes the loop to cinch down, I get no noticeable difference in catch-rate using the closed knot versus the loop. Granted, I reserve the right to change that opinion at any point! ;) You never know -- all it takes is one experience to change your mind about something right?
I appreciate the interesting points --
Gene