Originally Posted by justein
Is it possible to downgrade iOS beta 6.1 to 6.0.1 with an iPhone 4S? Any of the betas.
On iOS 6 and beyond, on an iPhone 4S, you may restore only to the firmware that Apple is signing to the general public. As of right now, that is 6.0.1.
When 6.1 is released to the public and is being signed, 6.0.1 will no longer be signed for the 4S, thus you will no longer be able to downgrade.
As a developer, you can read more about using a developer device and developer software here