Well I haven't heard of anyone who's had one replaced have a second failure yet. I had mine done at like 40k and I'm at 75k now with no problems or signs of problems. They had a bad part and it seems like the new design doesn't have the failures of the original part.

The H23 tensioner works as well and surely has less risk of failure but at the same time isn't as plug and play as the H22 autotensioner.