Yes, it’s been around that long. Diet Coke first hit store shelves back in 1982. Long-suffering dieters, sick of saccharine colas with aftertaste that lingered for weeks, embraced the aspartame-sweetened brew—and it’s been the No. 1 seller in its category ever since. But while keeping the 29-year-old formula is de rigueur, a can design from the Reagan era is a bit less plausible. So Coke’s done some periodical tweaking. The new design, first reported on by Adweek, which walks the fine line between heritage homage and hipster minimalism, will make its limited-edition debut this fall. But does it work? We asked eight top designers and brand makers to give us their unsweetened opinions.