I have them on the crew trap. I got them thinking that they were a no-cut option for going adjustable.
It turns out that they don't provide enough up-tension on the trap ring when they're hung low. My crew is often coming unhooked while sitting on the deck. This hasn't caused a problem yet, but it's worrisome. Thinking about the geometry, they'll probably work fine if the trap lines were cut about a foot shorter. I'm going to replace my trap lines anyway at the end of this season.