The biggest issue for me, when FB moved away from chronological ordering, was that if I clicked on a post in my feed, I could no longer go back to the feed and

The biggest issue for me, when FB moved away from chronological ordering, was that if I clicked on a post in my feed, I could no longer go back to the feed and continue browsing where I left off, because the ordering appeared to change when the page was refreshed. I pretty much stopped using the service around that time, and though I didn't actually think about it, I think this change was a big factor in that.