Having just come back from the movie... Sunset Shimmer disappointed me. I felt that she was a pretty flat character without much depth or implication of depth, and I've come to expect depth from MLP. Having been in love with the design since her toy was first revealed, I wanted to love her, or, failing that, to hate her but be entertained by her, but, in the end, she just doesn't do anything for me. Once you take away her dominating others through fear and/or power, there's just not enough left to really care.