I've been trying to think this one over, and I'm not sure I've come to any satisfying conclusions about Very Long Sentences. Not in the way that I have about, say, dried banana chips, which I've decided I don't like. Or cats, which I like very much. Or trees, goldfish, fingernail polish, adverbs. (I like adverbs, personally.)
But Very Long Sentences, now.... Sometimes, as a reader and writer, when I'm in mood to be impressed with some author for having strung together in such an artful way so many various clauses and ideas -- and the em dash really is quite dexterous because absolutely anything can go inside its little brackets, like a magic pocket in which you can stash whole cities, whole universes even, all safely nested in your original and more or less relevant idea -- I feel exhilarated from the journey, from following the twisty passage of someone's mind, marked so generously by punctuation.
And sometimes Very Long Sentences just tire me out. Sometimes I find them pretentious and distasteful. And confusing! Or not confusing but obnoxious. Often I skip them.
And the worst thing is that the same sentence can have both effects at varying moments. Which leads me to wonder whether there's nothing inherently worthy or unworthy about Very Long Sentences. Whether it's not all in my head.
So, I fall back on statistics. I feel I need hard-ish numbers. People who like Very Long Sentences and people who don't. Tally them up and see who wins, and we'll go -- quite democratically -- with the majority.