The top scroll wheel on my Canon 60D is set to change the shutter speed in video mode by default. I usually shoot at 24fps with a shutter speed of 1/48s. I normally wouldn't need that top scroll wheel to change shutter speed, but in my case, would much rather have it change ISO values.
That is just one of the many possibilities, combinations, and benefits you can have to button remapping. It would be great to have a ML button remapping option that allows you to completely swap button functions and organize the button layout to your personal preference.
Thank you, for taking the time to read this post! Any feedback, comments, or answers are appreciated. :)