I cannot find out which one will never fail on me. My qad was working great, but today it conked out(again). I have no confidence it it at all. I need to be able to trust my equipment so when that bruiser cruises up underneath my stand I'll be ready. So, what drop away will NEVER fail. I see many benefits to the muzzy zero effects. I.e. the arrow fires, the rest drops-no matter what. But most people say they are a hassle. But all other rests with timing cords and the like seem like they could fail just as easily as my qad. But then again getting a 110$ scizzor rest may be better than a 50$ qad. Thanks for the info.