> I think the most obvious evidence that these prosthetics do not constitute an advantage is the times of other athletes using identical limbs. Pistorius is whole seconds faster than his nearest rivals. If the limbs constitute a meaningful advantage, then why is Pistorius so uniquely quick?

You're mixing apples and oranges here.

In the highest most competitive horse races, it's not uncommon to still see horses that win by large margins. Having a horse win without advantage against other horses is not a good reason to start having humans race against horses.