For reasons that I won't explain, I think you are right about the FH being a better literary work than AS.
I also agree that her work in politics was not original because most of that work was already done by the others. Her achievement was to provide an ethical base for Capitalism without which it would perish in time. Her greatest achievements are in ethics and epistemology.
I disagree that "she oversimplifies and makes false dichotomies" and I believe that that view confesses a failure to understand the scope of her ideas. She has identified the fundamental error of Kant and his whole system of ideas has collapsed but most intellectuals today are incapable of seeing it. She didn't waste time arguing all the ways Kant is wrong and left that for others to do so the modern intellectuals dismiss her as "unsophisticated" and claim she didn't understand Kant when it is really the other way around.
What she did do was identify the fundamental principles at the base of any philosophy; the primacy of consciousness versus the primacy of existence. This is the battle today and the four philosophers who have staked out consistent positions are Plato/Kant (primacy of consciousness) and Aristotle/Rand (primacy of existence) so if its not obvious, I think she is a philosopher of first rank :-)