Royal-X and Royal-Lite, or any of the triple layer polyethalyne materials, such as Mad River's "Triple Tough," are hardly "junk." While they are heavier that Kevlar, they are far, far tougher, and resist punctures and compression cracks... they are also easy to repair in the field. I have use pretty much every material used for canoe construction and would recommended triple layer poly for most hunting/river applications. A good yoke goes a long way to managing the extra weight.
For flat-water/Portage tripping, it is hard to beat Kevlar.
Yea just prior to you post I edited mine to avoid a bad generalization...