Firstly, doesn't the aesthetic consideration depend upon the context?

However, to answer your question directly: I simply don't like how the em dash looks in the common usage of setting aside a clause; it always feels like it is drawing too much emphasis or attention to the two immediately enclosing words, rather than separating entire clauses... also, ideally, I'd want nesting (like you get from parentheses)))

I end up overusing commas for that, because I do most of my rambling from keyboard layouts, where only two punctuation marks are first-class citizens like the letters, and the remainder all require more effort.

Short dash is good for me. I feel like the longer one should just be ---