I can't see a use for them, except perhaps under my yard. Since feeders are meant to be kept short so that voltage losses are minimal, the use of a block might extend some of them beyond the loss of a half-to-a-full volt in places other than under a yard. That is to say, I prefer to use insulation displacement pliers on my bus and solder feeder ends at those bared sites...right where I need 'em.