Our party has pretty well gone synthetic, mostly with line that can be braided or spliced. A lot of slippage issues can be solved by using knots appropriate to ones material. If one can get past the classic 7 or 8 BoyScout knots and into an advanced knot tying book, he can yank rigs out of the mud and still untie his lines with ease. There are some mighty fine knots out there that have only been around for 6 or 8 years. Many are specific to ones material.
As to tight highlines if one has strecthy material, one can thoroughly wet his lines and easily end up with bowstring tight rigging as it dries.
