Just updated from 6.11.5 20 minutes ago, 37 containers 4VMs, couple of custom mods to go-file (borg, borgmatic, zsh, omz, nano, auto start encrypted disk).
Ran the Update Assistant (that is a part of CA Fix Common Problems), it recommended me to remove 1 plugin (of 25); Corsair PSU Stats.
Booted up, and business as usual.
Only thing I've noticed, Docker Folders doesn't seem to work on the Dashboard.
I've been through every RC on my test-server as well, and haven't really had any issues there either.
I've been running since RC1, no issues on my end but of course everyones setup is different, give it a couple of weeks to be safe and make sure you update all your plug-ins and take a backup beforehand as there are some significant and potentially breaking changes made in this version.
I have two unRaid systems - one is mostly a media server. The other handles backups and runs Scrypted (which is awesome - I have all of my cameras viewable on Echo Show's now). I updated my Scrypted system. The only problem I ran into was that NUT plugin was not compatible.
I will let it run a while before considering the upgrade of my media server. I won't be using ZFS on it, so no hurry and no major feature I need.