She's a walking tsundere cliché. I really find nothing interesting about her. While the characters in P4 are less realistic than P3's, they were still interesting enough to be great, subverting many Japanese media stereotypes. Besides the joke that her poems get constantly read by others, which is beaten to death, I really found her to be a very weak addition to the plot.
Oh yeah, and that's another reason why I dislike her. (SPOILER)She is introduced into the main plot, not just a social link. She is given incredible importance, even though the story was fine and self-contained without her. And the way her social links were done - how all your friends like her so much, implying that, hey, she's so cool, you should love her too - she's the walking definition of a Mary Sue. Bottom line: she's exactly what you'd find in a P4 self-insert fanfic. And not one of the good ones.