For those who upgraded, no need to do a restore. You can just option-click "Update" and downgrade the OS back to 8.0.0.
Instructions: https://gist.github.com/locriani/f0f5f4f71a28945c3750
Instructions: https://gist.github.com/locriani/f0f5f4f71a28945c3750
[1] http://9to5mac.com/2014/09/24/apple-ios-8-downgrade-instruct...