Hi, So I just checked sammobile and they are already rolling out 4.3 updates on my S4 on my carrier. How do I revert back to 4.2 if I don't like the 4.3 update? Will NAND backup suffice? Will it backup everything from OS to apps and data? I heard that knoxx will mess up the bootloader so it's hard to revert. Please advise some techniques before I go on with the update. Thanks!