Update is already there -
omv-release-upgrade. While I have had plenty of successful upgrades, nothing beats a fresh install.
I also like to use a different hard drive in case the upgrade fails. Use clonezilla and upgrade the copy. Another option is to make an image and run it in a vm. Then you can still see all of your setting. Ya I know I am paranoid. LOL
If you make it idiot proof, somebody will build a better idiot.