I disagree Bob, and I am pretty good at the flop.
I hit the line before ding and usually stiff anything under 20 yards.
E.G. a 12 yard shot from 40-50% rough I hit the full 20 yard flop with BS.
E.G a 12 yard flop from a perfect lie, I hit 70 - 75 % power on the 20 yard flop. Full BS
Rough up to 30% makes no difference with the Cleveland wedges.
I tend to avoid flopping over 20 yards, as it is more unreliable than a pitch, punch or full shot.