The first thing you missed is the right forum. This is the Classifieds forum. ;-)
I won't get into certified or STC requirements, but system-wise it's really up to you. Obviously, in a perfect world, you'd like to be up to date on the latest bug fixes and capabilites. But if you aren't having issues, the need isn’t critical. There's also a significant body of evidence that being an early adopter of new updates can sometimes introduce new bugs that weren't anticipated. I tend to delay updates unless I have a significant need. The difficulty doesn’t really change much from database updates, but there is more potential for problems. Most of those tend to center around USB drives and size/space limitations. There's plenty of history and help resources in the experimental forums, should you experience any problems.