Spent part of the weekend replenishing -- P-Haze's are one of my favorite, go too patterns. Poly-yarn is definitely easier, but I'm still undecided as to which looks better, fishes better and lasts longer... what say you? Excuse the photo's not my area of specialty.
Poly, 100 times out of 100, although the calf tail does look very nice here. Poly is easier to tie with (no stacking - if you've ever tried it you know how much "fun" that is), less bulky, sheds water, cheap and you don't have to go through a bunch at the shop to find the right consistency (there' can be a huge difference from one to the next).
I'll still use calf tail for stuff like Wulffs (#14 and larger) because it just looks better to me, but for 'chutes, give me the synth.