LuckyLefty,
My wife is about to replace her Force with a Screamin. From what I have seen the two balls roll almost identical with a bit more of a skid / snap reaction from the Screamin. Since she throws really hard (avg. 18mph at the deck) I am expecting very little difference in overall ball reaction for her.
It is my guess that the slower speed bowler / early roll drill / you saw is probably giving the ball more of a chance to react than you would normally see. You will get slightly stronger backend and hit with the Screamin (100% based on Reactor vs. Typhoon) IMO, but not much.