I almost bought the wrong 6D today...didn't know there were differences

Rick, I use an AMOD GPS data logger (under $100) which synchronizes with the clock in the camera and records GPS locations on a regular basis depending on how you set it. Then, when you get home, you use any of a number of programs to download the GPS data to the exif file. The AMOD runs on three AAA batteries which last for several days. This has been a godsend for my photography. I never have to wonder where I was when I took a photo, especially when I am wandering the logging roads of Michigan's Upper Peninsula looking for fall color.