Ray this test is indicative of what I see all the time as typical of the 2 formats. Do you believe me?
Instead of asking me if I believe you, you should be asking yourself what it is about those two eyes that makes one of them more appealing than the other.
Having examined both crops, I see nothing but make-up, lighting and perspective differences. In the DB shot, the eye has mascara on the lower lid, the white of the eye is brighter and perhaps most important of all, the pupil has a specral highlight.
There are a few other things that probably contribute to the greater appeal of the DB eye. It's at a slight angle and it's slightly larger within the frame.
None of the above characteristic necessarily have anything to do with format, except
, if you have difficulty in seeing what you are shooting then that could be the cause of getting a misplaced highlight in the eye. But I'm sure you know that the 1Ds3 can be used tethered, or if that's too much hassle, can be used in LiveView mode which allows for enlargement of the subject on the camera's LCD screen and very precise manual focussing.
Just to make what I'm saying clearer, I've modified the 35mm shot transferring the specral highlight from one eye to the other and lightened the white of the eye in the 35mm shot. I think you'd agree the 35mm shot now looks better and that a misplaced highlight has nothing to do with camera format.