In modern times, the use of hardbats is rare at the top levels of the sport, due to the reduced spin and speed they can generate. However, some players enjoy playing in hardbat events because they believe the reduced spin and speed allow for longer rallies and more interesting use of tactics. Players who favor hardbats over sponge rackets are often known as ‘hardbatters’.
Hardbat events are held in America, England, France, Germany and Italy (thanks to Scott Gordon for this tidbit of information). You can find the USA’s Classic Hardbat Table Tennis website here.