I’m considering moving my Rockstor install to new hardware.
My plan is:
Go to System > Config Backup on the old machine, and export the config.
Install Rockstor onto the new machine (which will be a newer version than my old machine), move all my data disks over, then import the config file.
Is it that simple - and am I missing anything? Does the config file contain all the info about my disks/pools/shares/RAID/etc?
Almost that easy.
Before running the config file, you want to actually import your pool. Once that’s done your shares will be there. Now you can run the restore config.
https://rockstor.com/docs/howtos/reinstall.html#data-import
and in the restoration steps, this pre-steps are highlighted as well:
https://rockstor.com/docs/interface/system/config_backup.html#special-notes-on-configuration-restore
Depending on where you had your Rockon Root (e.g. on the OS drive and not the pool) you might have to pre-create that one as well, otherwise the Rockon restore portion will likely fail. Or, e.g., a transcode directory for the Plex Rockon was created on the OS drive (that’s how I had done it, since the OS drive was an SSD and the storage drives were not).
But, apart from the above considerations, it should be that easy. I would recommend, since the next stable release is not quite out yet, to move to the latest test (5.0.13-0) before the restore, as there was a small bug in the config restore in one of the earlier test releases.
Great, thanks very much 
EDIT, whoops I didn’t realise this was already documented 