I say,
1) Do not be on the latest release unless, you have issues that it is proven to fix. (let others prove its issues before you use it)
2) Do not upgrade until you know the known issues it will cause.
3) Be on the release you have now, unless you have an issue that you can not deal with.
4) Upgrade when you have an issue that needs support and Avaya will not support your current release.
5) Pray before, during, and after all upgrades.
6) It takes an hour to upgrade, and days to test how it went. Be prepared to go back to deal with issues.
7) Charge for upgrades labor.
8) Do upgrades while your support outlets are available.
9) If you have a ticket open on an issue, and they tell you to upgrade to fix it, do the upgrade while on the phone with them, and test it before you hang up.
Remember, if it was not an inconvenience, we would not get paid. Sometimes we get paid by the head ache.
You do not always get what you pay for, but you never get what you do not pay for.