The old wisdom was: don't update until you know the need. Updates, after all, can create new problems, and they take time. The old wisdom is, I think, no longer wise. Modern software development techniques make updates safer and better -- not perfect of course, but less hazardous. And, today, you're unlikely to know every corner of the system that will improve when you update.
Improvements that seem minor and technical can often lead to big changes. Recently, we discovered that one of Tinderbox's support classes lacked a clone method: LongValue::Clone() was using the algorithm it inherited from Value::Clone(). This works fine -- it's a little slower than it needs to be, it does a little bit of extra work, but it's fine. Except that, obscurely, it leads numerical attributes to be sorted in lexicographical order and not numerical order. Fixing this took seconds, Tinderbox is now slightly faster, the code is a little sounder -- and a sorting problem has been solved as a side-effect. For most people, only the sorting question is going to matter. But it's entirely possibly that the update documentation wouldn't mention sorting, because that wasn't the problem Development set out to cure!
So set aside some time each week. Update your system. Get the current versions of your programs. And budget for a new computer, keeping in mind that computers wear our in 3 years -- 2 years if you're a pro.