Mei being all lively and cheerful was quite a contrast to her, demure, silent and withdrawn self we've come to know in the original anime. Just goes to show you that Misaki's death had an enormous impact on her and probably scarred her for life, especially since she saw it coming (which makes her attitude in the show even more understandable).
I liked the throwback to the first episode, where Mei and Kouichi first met.