Apple hopes to make your personal information more secure on your iOS and Mac devices, as well as making it easier to access in one manageable place. Apple understands that there will be some confusion at first with its new iCloud Keychain service, but whatever problem you have they aim to resolve it.
This is good in theory, but things never work out the way they are meant to because we can see from two of the points Apple has made on its help page has created yet more confusion. All is not lost though, because there is still a great community of people willing to help out.
Many of the iCloud Keychain issues concern how your saved password can sync with shared devices, but not across iCloud. Some users believe this is not possible because you need to share the information over the Cloud in order to do so, but this is not the case. This is better explained on MacRumors Forums.
The reaction to this is not in favor of Apple because Forum members believe that Apple has been vague on the iCloud Security Code and feels as though they need to make things much clearer.
As yet we have not set up iCloud, as we did not wish to encounter issues because of it being such a new service. However, it will not be long before we start to use the new iCloud Keychain across our various iOS and Mac devices.
Also See: iMessage not working with Mac sync