neubaer Thanks for the detailed answer.
First I will tell you what I did.
Basically when sysupgrade asked me to overwrite files I think I replied to overwrite to most of them. That was my mistake. But again, I hope there is a way to revert this, maybe though /var/backups?
Second, Your messaage is very clear until I hit this: "The sets in "NetBSD-daily/netbsd-9/latest" are the daily builds of STABLE branch of NetBSD 9, so updating once a week with sysupgrade is approximately like updating a Linux distro."
I don't understand since I expected that the daily builds are from the CURRENT, not the stable. Why making daily builds of STABLE ???
Also wasn't runnning a rolling release like being on CURRENT?