By making sure that all your het pieds are cinnamons, you increase the chances of producing female cinny het pieds from 1/4 to 1/2 per egg. Even without the bonus pewter het pieds, that'd be worth the price of the ticket, I think!

(side note: we don't call sterlings and silver streaks the same thing. Are we going to be calling both super black pastel pieds AND super cinnamon pieds pandas as well?)