I have tried, on and off, with using banks. I tend to make many changes and since Nikon does not give you an option of returning to your original settings (without reloading them from a memory card), I continually screw up what I had. Although I am still trying to get to use the banks, I think I am now moving back to the fact that one bank is less complicated.
I could see another bank being just set up for someone who you want to hand your camera to and just use it as a point and shoot. My normal shooting style has back button focusing and that would be difficult to use if I asked my wife to take a picture.
Maybe someone will have the magic thoughts that could get me enthused about banks but currently I am not.
I can't help but wonder why Nikon doesn't make this easier by allowing you to save your settings and then if you wanted to make changes ask you to verify that the savings should be saved.