I hate the damn things, along with most of the other gimmicky features popular on .45's and other custom firearms today. People seem to think just because something is expensive and looks different, it must be worthwhile. Or, they dream up a one-in-ten-billion scenario where their favorite gimmick offers some theoretical 1% advantage, and use that as justification for spending $500 on butchering up perfectly good firearms.
Speaking of one-in-ten-billion scenarios, anybody ever heard of something called "notch effect"? This is something engineers, metallurgists, die designers, etc. sometimes have to think about. Basically, if you cut a notch or groove in a piece of metal, that acts as a stress concentrator and increases the likelihood of the metal breaking at that point. Especially if the notch or groove has a sharp "V" shaped bottom.
Looking at a M1911 type slide, if there was any stress from the thing smacking back against the frame, it would already be concentrated right where the "spring housing" section at the front of the slide steps up to the longer main section of the slide. There is already sort of a natural, unavoidable "notch" at that point.
So why the heck would anybody want to go cutting any additional notches up the sides of the slide in this same area?