The issue IMO though, is if you are using a USB key, it must remain in the computer or the computer cannot be auto-updated (with restart).
While I am not a big fan of auto-updating, I have my servers set that way because I ignore them for weeks to months at a time, and they need updating. Any auto-restart would lock up the server without the key.
If the key were present, then there is functionally no encryption if the computer were stolen, so what's the advantage?
