Time and time again, procrastination pays off. Sometimes I resist upgrading something because of annoying breaking changes.
Often, the impact of those changes is lessened in subsequent releases, making the dreaded upgrade a lot less painful.
Don't upgrade now what you can upgrade tomorrow. It'll be easier!*
*security patches excluded (and often they get backported so you can dodge the breaking changes in style!)
Consult your system administrator to determine if Procrastination™ is for you.