I use 30# Fireline for the dropper loop on shanks and it seems to be "Goldilocks" for stiffness. I've heard from other tubers that they like the way they can position the hook up or down. However, I was never convinced that the hook stays positioned all the way through a swing with just a pair of lead eyes for geotaxsis. Also, it takes me a couple times to get the loop size correct on a tube stream side. I suppose I could get better with practice. Too many times I just saw "that's close enough!" and cast with the hook flopping well beyond the junction tube. I've caught fish that way too.