I have always set my color picker to HSB in Photoshop. It seems very intuitive when thinking of color in terms of traditional painting.
Here I am playing around with the picker set to RGB. I am surprised with how significantly it effects my color choices.
It seems to lend itself to a broader spectrum of color, whereas with HSB I tend to adopt a much more limited palette. I think HSB requires more intentional color selection, where the RGB slider naturally introduces a greater range of hues. I probably just lack restraint though, and need to practice with it more.
I remember reading Lin Ran's great tutorial on RGB color picker a few years ago:
Link
At the time I didn't understand the complexity of the RGB slider. It was just too overwhelming to bother with. Now it feels very natural to use. I think I'll keep playing with it.