I know the owner of proforged personally and the products that he provides are of very good quality and performance, But the main difference between the rubber (oe) and the aftermarket polyurathane LCA bushings whether it be from us, proforged, energy or prothane is the construction of the bushing. OE rubber bushings are vulcanized to the inner and outer shells. Making a permanent bond. Making the only give or rotation come from the rubber twisting on itself. Where as with the polyurethanes, are a insert so just like ours, proforged LCA bushing are pressed together and the inner sleeve moves independently of the poly bushing.
Thanks
James