I've always been of the opinion that belts and pulleys are somewhat cheaper to manufacture than chains and sprockets and are generally quieter running.
But in the case of the Supercut there were so many different configurations made so as to suit a particular client that SB would've made whatever you wanted within the budget range. The Supercut was probably their most adaptable machine made as it was a Professional unit that was also sold as semi domestic, thus the smaller sizes produced eg. 14 inch variant.
Cheers,
BB.
