Both images were shot at ISO 100. I have to agree that in general the 5D image is superior in lots of subtle ways, but there's still a question as to how significant these differences are, after skillful processing in PS
And that's exactly what my original question was about. I believe we can conclude that:
1) it is significant when comparing 5D vs 20D, and likely can be extrapolated to comparisons with other designs/brands,
2) in general most people don't see the differences, because the camera or RAW conversion does most of that processing for you already,
3) for high-end needs it is certainly worth the money, but in many other cases it remains questionable,
4) a 26mpx 1 series will not make the grade in the foreseeable future. 22mpx may be stretching it already,
and, most importantly:
5) there is no reason to suspect a potential degradation in image quality when jumping from 8mpx to 10mpx in APS-C, solely based on pixel-bin size differences. Image quality was bad to begin with
Since this new thread was started in order to examine real world implications of different sensor sizes, I really believe that the significance of these differences ultimately should relate to specific print sizes, but that would take a lot of time, ink and paper and I'm now preparing for my next photographic trip to SE Asia.
Well, happy shooting, have a save one, and bring us back some nice images, because ultimately that is what this really is about, ain't it?