I call the kit at top somewhat hyped. "Make your car safer" with a picture of a car doing a burn out. There are actually instances where an open diff is safer but over all, a LSD gives you more mobility. If you are on an icy / slick left to right slant, an open diff can spin one wheel while the non spinning wheel keeps the car from sliding. On an LSD diff, the car will slide down the hill.

Same goes for level ground if the driver is on the throttle hard in a corner. ( See You Tube of people leaving a car show and ending up in a ditch. )

For the real bit of hype, this type of conversion has been around a while and won't last any length of time. Compare a exploded view of a real clutch type LSD and an open diff. The conversion is relying on 2 friction faces where a clutch type has about 10.

As for LSD oil, regular oil can be run in a clutch type diff. LSD oil has a friction modifier to eliminate parking lot speed tight turn growl / pop.