I first encountered U1 and U2 user settings back when I owned a Nikon D7000. It was such an incredible shortcut, and I have loved it on the D600 and now the Z 6. I miss it on the D810 and will one day take 10 minutes to understand how custom banks work.
My current set up allows easy switching between wildlife mode (full manual, auto ISO, continuous high burst shutter, and currently centre weighted metering); generic monochrome in manual mode; and high contrast monochrome (aperture priority, highlight weighted metering).
In the past I have struggled to remember what was what, resulting in a piece of tape stuck to the camera to remind me.
