Does any body really use this feature? Do you generally save them to a separate card, if not, you would lose them if you formated the card , wouldn't you?
In the past (1DMIIN), I have not saved to a card. The number of settings that I changed from the defualt was not that many.
In the MIII I did register two sets of C.Fn settings, plus basic settings, and then saved the camera settings to a small SD card which I keep in my card carrier....just in case.
Yes, if you format the card, the settings go away.
Save to card than download the file CAMSET01.CSD into a folder on my desktop computer. If I ever need access to the saved settings, download the file back on a CF card and go.