The first time I saw the Brass Scorpion conversion, I was amazed. The Defiler kit in itself is pretty cool, but the scorpion form was just so much cooler the the original!
A few months back I surfed the net, searching for cool Defiler conversions for my army, and came over a conversion using a Dark Eldar Raider and one-and-a-half Defiler as a Scorpion style Defiler.
I thought: "I've got to have one of those!" Unfortunately, the conversion requires two kits to make one, so I went out and bought three. This gives me enough parts for two conversions, and as I've said before; two Defilers are four times better than one.