I have been using the Munsell color model for almost thirty years. I became aware of it when I first began to explore the possibility of trying to do painting, about ten years after leaving art school. I had been so traumatized by the lack of technical instruction at the Phila. College of Art, now called the University of the Arts, that I was absolutely convinced I'd never be able to paint.
Somehow I garnered the courage to give it a shot and while exploring what paint to buy I became intrigued with a new paint product: Liquitex Modular Colors, based on Munsell notation. Rather than standard color names these paints came labeled according to their hue, value and chroma. I started using these paints and achieved good results almost right away. It forced me to think in terms of relative values and within a year I was painting illustrated covers for Time Magazine.
About ten years after I started painting I began a decade long, once-a-week, study with John Murray, a former student of Frank Reilly's. The HVC mindset I had been utilizing meshed perfectly with the Reilly methodology since he too used Munsell as his starting point. What I really liked best about Reilly's approach was that he adapted the Munsell value range to bridge the gap between black and white pigment. This made more sense, to me, since we painters are working with pigments. Munsell used theoretical black and whites since he wanted to be able to classify color for all types of industry and not just limit his system for artistic purposes. According to MUnsell, Ivory Black is value 1.5 and Titanium White is value 9.5.
My value 5 falls halfway between black and white pigment and is a true middle value, paint-wise. Munsell value 5 falls at value 4 on my chart and is too dark resulting in compressed dark value steps.
I hope this all makes sense.