Vanes are heavier than feathers... which reduces your arrows' FOC balance. Lower FOC = Less stable arrows.
Vanes are heavier than feathers.... which adds weight to your arrows and makes them fly slower.
Vanes aren't nearly as good at stabilizing an arrow as feathers are.
Straight fletching isn't nearly as good as helical at stabilizing an arrow.
With straight vanes, you've got the worst of everything. But, on the bright side, at least they're waterproof.
