Only problem with double-edged blades is that they're illegal in many states . . . including mine. Only way to get around that would be to make two versions . . . one single-edged and one double-edged. That way everybody who wanted one could get one.
By the way, that's exactly what Boker does for the AF-12. AF-12s sold in CA are single-edged.
Illigal??? What the....I love my state