"If it ain't broke, don't fix it!" Not bad advice, but updating the BIOS is not a big deal if you know what you are doing. Whatever you do, DO NOT USE THE @BIOS UTILITY SUPPLIED BY GIGABYTE! There are too many things that can go wrong using this utility that could damage your motherboard.
The latest BIOS for that motherboard is F5. If you already have this version, then there is no reason to upgrade. If you are not using this version, then check at the Gigabyte website to determine what this update addresses. If it deals with things you have no intention of using, then don't update.
As dpual8 mentioned it is not really needed unless there is something not working properly but Gigabyte makes the process pretty much foolproof (since they have dual bios chips if something does go wrong with the flashing process the secondary bios will reset the primary one so that you can try again - so it is almost impossible to mess it up - so if it does need it do not be too afraid to try.