I'd still like to see a side-by-side comparison of the same photo taken with both the original 24-70mm lens and the newer mark II.
I trust that the LensRental review is both valid and reliable, yet I'm cognizant of the attitude of many (more knowledgeable) commentators on CR that are quick to dismiss numerical tests (DxO springs to mind) when they are loathe to accept the conclusions.
It would be interesting for many here if Roger or someone else at LensRental was to shoot a reference shot using both lenses at 24/35/50/70mm zoom levels
We now know that the mark II is a lot sharper and exhibits similar barrel distortion, but colour is the area that I'm most interested in (btw I sold my sharpest lens - the 70-200mm f/4L IS - because the colours were not as warm or vivid as my 24-70mm f/2.8L mark I) as this is a feature of 'L' glass that sets it apart.