When you say turn iCloud sync off, do you mean to turn it off for everything? ie Photos are no longer synced to the cloud?
I ask because I know people who have lost pictures when their iPhone locked up during an OS update and the phone needed to be restored. I've since told them to leave iCloud on, and then when they had their next iPhone lockup up and needed a restore, their pictures were easily recovered from iCloud.
I know you can set the iPhone to back up pictures to the computer every time you connect a cable, but a lot of people never connect a cable. So for them, leaving iCloud set to back up Pictures is a life saver. (or photo saver anyway).