I would argue that the differences are so great that Mises and Hayek don’t really count as “libertarian” at all, as that label is usually applied today. A competent, useful article on this topic might seek to explain why so many of today’s libertarians seem to reject Mises and Hayek’s argument that democracy is a life-or-death matter and an utter necessity for a liberal social order of peaceful cooperation, even if there are serious problems inherent in democratic politics.
Fishing for fascists: Libertarianism and democracy | The Economist