[edit - it stops after a while]
Regarding: "The etc sets are now gone. All the sample /etc files are now included in the base set. This should make sysmerge must [sic] easier and faster in the future, since there will be many fewer conflicts to resolve. On the other hand, even rc and rc.conf are now overwritten, so it’s not possible to maintain local mods without additional work. This makes sense, though, since /etc/rc is as much a part of the base system as /sbin/init. You don’t want to be running a five year old edition."
I thought (and the manpages always indicated) that the rule was that /etc/rc and /etc/rc.conf were fair game, and that if you wanted to make changes that weren't overwritten by a system upgrade, to put them in /etc/rc.local and /etc/rc.conf.local. I'm unclear why this is considered a problem.