Sandy Bridge CPUs and Cougar Point boards are still new products. As such, you should still be upgrading to the newest BIOSes at the earliest opportunity. They are still working out the kinks and giving performance/stability boosts and new features.
By six months after the release (in this case August), things should be stabilized. Then you can do the "If it ain't broke, don't fix it" thing.
And flashing the BIOS after you have it set up shouldn't harm anything.