I have been using 6.7.0-rc7 since release and I only had a couple issues that I put down as 1. being a nooby to unraid 2. being rc7 or my system, and 3. These issues are minor.
The issues I had with rc7 were...
1. The unRaid GUI would hang for an unknown reason to me. My fix...log out, log in, this would often resolve it, but worst case I would reboot to fix the hang. What I mean by hang is the GUI seemed to respond changing menus etc but changing settings etc and selecting apply would not do anything. Once again not sure if becasue of using rc7 or my system.
2. Plex, not wanting to start or not wanting to display the Plex GUI correctly. My fix...stop the docker, log out, log in, and re-enable docker again, then Plex would display correctly.
3. Plex does not seem to work correctly if the majority of the drive array have spun down. Plex seems to be sluggish if not stop if the array is spun down. Once the array is spun up Plex runs like a charm.
I have now within 10min of this post updated to 6.7.0 stable and so far (with a quick check) all my plugins and dockers are working fine, but will be looking out for the minor issues as mentioned above if they occur over the next week or so.
Still loving unRaid!!!