Seeing all the stuff about Line Reactors lately, just thought I'd tell my experience with 'em. My roomate's friend was out visiting and skiing at Alta for the last week. He had a new line setup with the Reactor 10s on some Assasins. He was constantly pre-releasing, he had miss ski time to get them worked on because the brakes got all screwed up, and still had the problem after cranking them up to 8.5 or so. His pair were blatantly defective, I'd go and demand my money back if I were him.
ACLs are important, but pre-releases can be very dangerous. You have to be able to trust your binding, and I can't trust them after what I saw this week.