Speeking of the ZF-lenses only, I think the answer isn't that easy. Some of their lenses are outstanding but others aren't any better than comparable MF-Nikkors. Examples of the less impressive ones are 2,8/25mm, 1,4/50mm and 1,4/85mm. Incidently, all of them inherited their optics from Yashica/Contax lenses from the seventies. The younger lenses are generally better if not outstanding.