I've seen a couple short demo vids. It looks like a hand held torch, similar to a conventional MIG, connected to a power unit via fiber optics. Does anyone have any experience using one? does it require gas shielding? Any special material prep? I would think it would have a smaller heat affected zone, less warpage, and be less likely for welds to crack later on in thin sheet or pipe, like exhausts and such. And no sparks! Probably absurdly expensive, but no doubt will get cheaper over time.