The Case--Please Hear Me Out--Against the Em Dash.
As much as I love the em dash, I will admit that over the years I've become aware visually when I've used them too liberally. They become the punctuation equivalent of an echo, which occurs when an author uses a word soon after already using it so that the reader is aware of the repetition. Therefore, I've tried to cut back on them for that reason.
Otherwise, I'd be sprinkling them in paragraphs like jimmies on cupcakes.