We have a very small IT team and consulting budget is zero for technology. We have found the upgrades are pretty bullet proof and generally quite simple in terms of execution (read the upgrade doc and follow).
* If you are virtual - it doesn't get much simpler in terms of pure upgrade.
* Test - and then Test - they upgrade will work - and that is likely what you are paying for. If you have issues in your test environment after upgrading - then use your precious consulting budget if you can resolve via the community or support.
* Honestly - as far as Upgrades go - the product is better than most.
Terry