I just love when simple thoughts come to the simple-minded like myself, usually after the fact as well. Here goes:
One cause of the shudder could be improperlly-toed brake shoes. If those front brake shoes are properlly toed-in, as they are on my Cannondale, they will provide silky-smooth stopping and slowing, as they do. If they are improperly toed-in, they will most likelly provide the front-end shutter as described in the opening post of this thread.