The question is do you "need" to upgrade. The answer is Maybe. There are a lot of good reasons to upgrade and in general, the advantages (new features & bug fixes) outweigh the negatives.
As with all new releases, there are bug fixes. So the stability and operating experience is intrinsically better with newer releases.
However, there is one reason we will make you upgrade to the latest version. If you report an issue via the HelpDesk, we only expend resources investigating issues on the current software release, as we are not going to go back and fix a problem in an older point release if it does not exist in the current release.
Occasionally a new defect may creep into a new release that affects you. This is one reason we have made it convenient to run previous releases with a simple and automatic firmware update.