I've read both of them. Again, influential does not = good. Legitimacy crisis is interesting but he backs himself into a wall with his whole discourse ethics/public sphere/communicative action thing. Assuming clearly bounded political communities and other forms of solipsism plague all political theories that have no theory of the international. And don't get me started on Rawls' figurative and ideal "Law of the Peoples" crap... how does that give us a politics or help us fight injustice in anyway? No wonder people don't take political theory seriously when this sort of crap dominates.