I believe the "Fathers of the Comparadun" state that they began to fish a hackled comparadun more than the deer hair versions. At least, I know they preferred such on slack, clear water.
I like that idea, but also like the idea of a trailing shuck representing the fly as a cripple which seems to make them especially appealing to a trout.

This is a hurriedly tied version of a Hackled Sparkle Dun