Well, I have been a fierce defender of my beloved A1 for the last few months.
But somehow I keep noticing that the 7D images seem to have a better "transparency". As if the light was indeed captured better.
It might just be an illusion, because I have seen some very beautifull A1/A2 pictures too. But it might also be that the enhanced dynamic range of the 7D provides a better/cleaner contrast in the mid tones that is sufficient to give better images...