Upgrade
So, I went ahead and upgraded to Sierra yesterday. A few folks had attempted to upgrade and had not had too many issues, so I went with it. Very smooth update for the most part, the machine had to reboot a couple of times before I felt like it was done, but that's fine.
One thing that did change, however, was the lack of my Keychain enabled private keys to be loaded into my ssh-agent
when the computer rebooted.