Never used them, don't think they are worth it.
They make steel dies and unless you're hung up on the traditional, messy case lube, I don't see the aversion to using them.
Hell, if you have several handguns with the same chambering, its nice to make all the ammo you have reloaded run in every one of them. That isn't always possible with carbide dies, which is another reason these new dies were created.
