I am the same. I don't know how anyone could be a regular user of a Canon digital camera and not use My Menu.
My only complaints with My Menu is that not everything can go there and that not all settings are in the menu system. There's also the lack of consistecy across all levels of camera (for no apparent reason.)
I would love to be able to lock various settings so that on cameras where shutter speed, aperture and ISO are easily modified, that accidental knocks or turns didn't modify them.
I guess it depends on if you make a lot of system menu changes.
For the most part, once I have my camera set up, I rarely go into the menu system for anything really.
I might pop in there if I want to set it to do a multi-exposure set of shots from time to time....I go in there to format my cards.
I shoot exclusively in RAW, so I don't have to worry about picture profiles, etc....
I will admit, I've never messed much with the different AF settings and honestly, I think I may try to pick a weekend and figure that out and see what all it can do, but to date, I've pretty much left that to default and haven't had a problem.
I really had never noticed the "My Menu" on the 5D3 I have....
I may to play with that too...always fun to discover new things about your tools/toys.
cayenne