It seemed to me that he just made up a character and gave it the name "Haldir," in order to fit into scenes that were also made up. Bad taste, imo.
And Aragorn was considerably weaker than the character in the book ... modern, conflicted, and all that.
I'll concede that Aragorn was more "modern and conflicted" in the movies... but there was self doubt in the book that was part of his character, even if it was expressed differently.
I don't get complaints with Haldir though... In his scenes at Lothlorien, his lines and attitude seem right out of the book. The only major deviation I can see is the plotline deviation that brought him to Helm's Deep. Is that what you two mean?