I had one go bad, think it just lost it's tension.. Slip had some trouble with them too, I remember.
I still use them, just change them out a little more frequently.
I had read a few people had issues with fish being able to back the plug off the snap, when doing a head shake.
I like em and feel more confident w/ them over any other snaps Ive used
Sooner or later you're going to realize just as I did that there's a difference between knowing the path and walking the path. - Morpheus