Originally Posted by imped4now
A body lift is a body lift, so go on price. JKS is the only body lift manufacturer to differentiate themselves by providing body lift spacers that cup the body mount and are rounded off (forget term) to fit in the tub. I see this design as theoretically more stable but I'm not sure if enough force is ever applied to a single mount to need this design. Nonetheless, I think it's worth the difference in cost.
Take a look at the Currie body lift. Unlike JKS, they are billet aluminum, not poly, and are powder coated. They too are concave to fit the mount better. We've run the Currie for four years without issue.