The aerodynamic design of the Impact lead helps put your bait out to the maximum distance and the wire formation keeps you there where the fish are.
This range of leads all use the Impact cone to release the baited hook from the integral bait clip on impact with the water.
The advantage of this method is that you know when the bait becomes unclipped and as the bait travels through the water its forced onto the hook bend and not up the trace length. All good rigs would still incorporate a bait stop.