'When I try adjusting the sliders-- saturation and noise reduction-- I really can't see any severe difference those adjustments make.'

I don't know about the GH2, but with my GH1 I see definite differences in the cameras response with the sliders and across the modes. Sometimes they are subtle, and sometimes not. I have found that Vivid, Nature and Dynamic have some color bleeding issues in some situations but can function well where the sun is blaring and bringing a well lit sense of contrast to the scene. And the fact that Nostalgic, Smooth, and Standard can nearly pop a full F-stop into the mix is telling. It means that the camera is capable of sensing a wider range of values than is present within modes. I originally thought the modes had little effect on the final image because the ability to set the values is limited to 2 in any direction. But this is very similar to the abilities of higher end cameras to set their matrices very precisely in order to achiev e specific looks and responses from the camera sensor.

So, after much experimentation, I see great possibilities with the modes and I'm not surprised that High Dynamic became a mode in itself in later versions of the camera. To hack the modes however may be harder than it seems because that would entail a very detailed understanding of their place in the overall interface of the original design of the processor/sensor mechanics. Using other panasonic cameras and the designs of their GUI's may yield a helpful hint or two--BUT that is a rather Herculean effort, I would say. I propose that maybe we get a petition in order--getting panny users to contribute together to ask Panasonic to expand the parameters of the modes and a more comprehensive explanation of their workings for Panny users. Maybe even give hackers a sort of universal master key to expedite the process of said expansion.... Perhaps it asks too much?... Maybe I'm wrong?