Well, to maintain the thread,
With Margulis, one must get the mood I think. Apart from his tendencie to lets us feel he is smart and that it is going to be easy, one has to (heurg...) ... work at it :-)
I am thinking of lab colors like when I paint (losing control) in a way that color has no value. Maybe it is a beginner habit.
A question comes up. What about all theese subtel color on a print? In sRGB?
The technical details are deceptively simple. A few points added to a curve, and a paragraph of explanation may seem like nothing much was done. It is important to use the images from the CD, and recreate what Dan describes. Then the big test is applying that knowledge to your own images.
Subtle colors are an issue for Lab, which is a very coarse color space. RGB is in the middle, with sRGB being the most subtle color space of all. CMYK allows very fine adjustment of color, and was the original reason for writing the Curvemeister plugin. I was very surprised that Lab became so important.