this, from The Atlantic, pretty well nails my experience (though the author just scaled back their Twitter use, vs. leaving entirely):

It’s faintly ridiculous just how much my quality of life has improved as a result. I now know much less about the latest controversy—but have much more time to read that book I’ve been meaning to turn to for ages. I miss out on a few good jokes or interesting links—but have started to detox from the feverish anger that reigns supreme on the hyper-political corners of the Twitterverse.