I've had two sets of Comp Xtreme-Energy lifters completely fail on me. The plunger spring broke on several of the lifters so I refuse to use Comp lifters anymore. If memory serves me, they were fairly noisy.
I refuse to use comp anything!! No comp junk for me. As much as some people hate mopar parts Id rather use the mopar parts. I have erson pushrods mopar cam stock non adjustable rockers and more importantly no comp stuff.