Same impression here. I just usually think of her as the misunderstood character out of the bunch. If you think about the reasons why she's doing whatever she is, she comes off as a character to be pitied because of the circumstances that brought upon her current situation. Though I do agree that her voice is pretty annoying, considering how loud it is.
In the end, we can always brush her off as that character that goes 'MOKYUUUUUUUUUUUUU DESU DESU'.