pell wrote a review of DMM Ultra OVAL Anti-Vibe Carabiner on August 7, 2014
Familiarity: I've used it several times
It was a curiousity is pushed me to get a DMM Ultra O Anti-Vibe binner. I was really wondering what is it and what is it for.
The first question has a pretty short answer - Anti-Vibe is just a screw-lock which gets more and more tight while being screwed on. One really needs to apply some force to make the last twist. Good news - there are some force needed to unscrew it. Thus Anti-Vibe lock most likely won't unlock due to binner movements back and forth along rock. The last is the answer for the second question - it is for an extra peace of mind when rigging an anchor.
Personally I found it to be a perfect top rope carabiner for cragging days, the best top piece carabiner for TR solo setup, the best micro traxion binner for pigs hauling.
I own one Ultra O Anti-Vibe and about to get the second for anchors power point.
I don't like it as belay binner for my Cinch - it takes a while to put it on and off and I found it to be a bit frustrating.
Bottom line. Highly recommended for anchors and hauling.