I'm looking to get a used LR3 and will be driving it on a nearby beach. It's hard to find a used SE with the heavy duty package. Most of the HSEs seem to have it but I prefer the SE with 18" wheels. Do I really need the locking rear differential for sand driving or is it more for rock crawling when one wheel is off the ground? IMHO, every LR3 should come with the heavy duty package...the full size spare alone justifies the cost.