I would love to see some testing on the different ferro rods. I suspect they are all made of the same material and all work the same.

In my experience the biggest determination in effectiveness is the user and the scrapper. I worked with most of our Pack last weekend with Coghlan's Emergency Tinder and several ferro rods and our Troop a few weeks ago using pitch-wood and several ferro rods. They all make good sparks and they all made fire.