I was watching some car show on public television and they were comparing LSD vs. electronic locking diff. Some of the new GM trucks have an electronic locker that engages if the sensor senses more than 100 rpm difference. It can engage at speeds up to 25 mph. They were doing an up hill test where the truck had to drive on one side which had metal rollers. They showed the rear wheel spinning on the rollers and the truck not moving. They kept referring to it has LSD instead of an open diff. I don't think a LSD would operate like that. With the locker the truck went up the hill with no problem over the rollers on the ground on one side.