This proves that for any tests other than hardware type tests that photozone does, it's a crap shoot. On photozone, they tested they 24-70L against the 28-70L and the lab tests showed that teh 28-70 was technically superior to the 24-70L. In Michael's tests, it's obvious that the 24-70 has an advantage, but where we go again with all the variables in an uncontrolled environment.
Also add the other tests that show a slight superiority ni the favour of the 24-70, and you'll have general mayhem.
But this is what clinches it for the 24-70:
- moisture/dust seals
- availability (you can buy it new)
- bokeh (according to some people, anyway)
Oops, that was a digression.
On the general point, I agree with you. I really miss Photodo, but even Photodo didn't take everything into consideration (bokeh, for instance, is completely missing, and vignetting isn't insignificant either).