It raises an interesting point (to me anyway) - the use of the Shadow/Highlight tool in CS3. Although I have CS3, I very rarely use it, preferring the PS7 (quicker and I'm use to it) version. I can simulate the new tool using Gamma and BlendIFs, but I'm not sure it is really the same.
So I think we have to be quite careful to differentiate between the tools and settings we use and the effect of the adjustment step we are trying to make.
I don't think there's anything in Photoshop that can compare to the Shadows/Highlight filter. The algorithm does an outstanding job of lightening shadows, and uses the values of surrounding pixels to average out the correction into a smooth transition that a curve can't match. With the image in LAB mode, it can do its magic on just the lightness, leaving the colours alone. I'd recommend you fire up CS3 (the filter appeared in CS2) and give it a try - it quickly improves even slightly too-light and too-dark images, not just the horrors that Greg tends to put in front of us. I use it as part of my workflow, in much the same way as I use CM. CM allows you to correct colour casts that are so subtle you can't really see them until you've fixed them. Shadows/Highlight allows you to lift shadows that you didn't even realise were too dark until you've fixed them.
OK, plug over. :)
As far as differentiating between tools is concerned, yes, I agree. But let's not lose track of the idea that this is a Curvemeister forum, not a Photoshop one. The question is, where can we use CM in a workflow to fix issues that are harder fix with other tools? Chris's workflow seems like a ideal candidate for analysis. He uses exotic blends and inverted this-that-and-the-other all over the place. I would ask, what are you trying to achieve with, for example, that inverted-blue-channel-in-overlay layer, and how can that effect be achieved in CM with a fraction of the effort?