I don't think Kuroneko and Kirino are that different from each other. They obviously have different tastes in anime and fashion and have different outlooks on the world but in terms of personality they're quite similar to each other. One of the most obvious examples of this I can think of is in episode 8 where both of them write a story that features the other being treated horribly and have virtually the same conversation with Kyousuke.
Even when Kuroneko was first introduced and before she had a line of dialogue, there were parallels between her and Kirino; during the female otaku meeting, she and Kirino were the only ones who didn't talk much.
In short, every time they argue it's basically tsundere vs tsundere; kind of an odd friendship.
That's part of what makes their interaction funny to me.