One public image advantage of plastination is that, if you're doing it on whole bodies, you could (Plausibly) put the plastinated patient on a standard bed (Maybe in a 2001-esque pod for extra effect (No, no need to mention Robert Nelson pulled the same stunt)) and make it look closer to real medicine. Though I'm not sure it's completely prudent to let a plastinated body out in the open collecting dust for show.