I have been running OMV for years and it is super stable. I rarely have to go in there. It has a lot of functionality thought the UI. My biggest gripe is that all of permissions options/ACLs combined with normal Linux permissions can be kind of confusing.
Unraid is also super simple, but maybe a bit too simple for some people. I don’t use anything but the core functionality in either one of these products. If you’re on the fence, you can do an unraid trial for 30* days (30 days, but technically you can stay on the trial as long as your disk array does not have to be restarted)