Used to waste so much time arguing on FB comments -- and now that I'm off of it all of that energy has been reclaimed. It's been a remarkably positive change in every way.
I got off Facebook a couple of years ago. A couple of months later, I got rid of my smart phone and went back to a Nokia 3310 for a full year. Actually was a huge relief and felt really good. I'm like many people here on HN, I suspect: I work a desk/computer job. My attitude: If I want something online, I'm in front of my computer 12-14 hours a day. If I'm not in front of my computer, then I WANT to be offline. If I'm offline, but you need to reach my for something important, you can text or call me.
One of the most interesting observations about not having a smart phone was not how my behavior changed, but how others behavior changed. As my friends became painfully aware that I don't have a smart phone, I'm not checking my email 24/7, their texts don't get read-receipts, and they don't see the ellipses as I type text replies... they became less demanding/insistent of my time (except for the urgent things, of course). It was really freeing.
I only got a smartphone again when I lost my Nokia 6 hours before I had to catch a plane for a week long trip -- I pulled an old smartphone out of my junk drawer, threw a SIM card in it real fast, and headed to the airport. I have hardly any apps on it now, and it's great.
