I put up a web page with some notes on LCH compared to HSV:
http://ninedegreesbelow.com/photography/lch-vs-hsv-for-picking-colors.html
I’d like to put together one or two tutorials on using LCH to pick colors, that hopefully could be tutorials for gimp.org and/or pixls.us, and would incorporate comments, input, images, and such from this thread.
As you all know, I tend to be too technical and too detail-oriented 
. So any input/help in writing actually useable tutorial(s) is greatly appreciated.
So far the tutorial notes somewhat cover these topics:
- Picking colors.
- GIMP’s new LCH color sliders (no details on how to use).
- A tour of GIMP’s sRGB-based HSV color wheel.
- The primary, secondary, and tertiary sRGB colors on the LCH color wheel.
- Making hue-based color palettes from a color wheel, with links to some excellent resources.
- Comparing LCH and HSV color palettes - next topic to be covered, no pictures or text yet.
In preparation for comparing LCH and HSV color palettes, I’ve made (but not yet posted) a bunch of monochrome color palettes. It’s been interesting to see when the HSV and LCH color palettes look similar and when they look very different, and also to encounter the “gamut limitations” the very small sRGB color gamut places on making LCH-based palettes.
Here are the three images from what I’ve put together so far (the tutorial notes have text explaining the images):
GIMP’s HSV, RGB, and LCH color sliders.
Left: GIMP’s sRGB HSV color wheel; Right: HSV Hue ring with color dots smarking every 30 “HSV Hue degrees”.
The sRGB HSV Hue ring wrapped around the LCH Color circle, showing the locations of the sRGB HSV primary, secondary, and tertiary colors on the HSV Hue ring, and also on the LCH Color circle.