There have been many installed now (many by me), and some should have many thousands of miles on them.

Have you personally experienced or seen one fail? I have not, so am beginning to really really like them, but want to temper my enthusiasm if it is misplaced.

No "I had a friend who's cousin knew a guy..." stories, please. Looking for real verifiable experiences.

 

I have never seen one fail, but of you torque down the spark plugs too tight it'd probably cause a failure.

 

Not sure if mine was a Timesert or Dorman but yes I had it spit the plug out with the adapter on the plug. Shop installed it, it couldn't be threaded back in. Not sure if they forgot the thread lock or what. It last a few years before it spit. #2 plug so it was easy to get to.