Quinto doesn't have a round face -- that would be Simon Pegg. Quinto has a longish, big-nosed face somewhat like Nimoy has, so there is a similarity of type. But his features make him look more like a young Dennis Quaid than a young Leonard Nimoy. The baby fat gives Quinto a doughier look than Nimoy, but most young actors today have that slightly doughy look, perhaps because of ethnic differences, perhaps because of lifestyle ones. Where I grew up, there were a lot of people that had that "chiseled," weathered look, along with straight dark hair like Nimoy's, all of which was considered quite masculine. Many were eastern European. Nowadays, we seem to prefer, or perhaps privilege, a different look.