Kisser buttons are actually not that consistent and are not worth the extra weight in my opinion. Positively no need for one if you have a peep sight, either one or the other. If you need both you have very inconsistent form and your peep is not located in the correct position.

I don't even use one if I shoot without a peep.

I have a buddy that has one and swears by it, won't shoot without it. Even though I have watched him endlessly anchor to a different spot from shot to shot and contort his face to find the kisser button. As many do, most do not use them right to begin with. Why you would want to anchor to the most inconsistent spot on your face is beyond me.

Get a No Peep, much more accurate and doesn't add weight to your string.

My opinions anyway.

Paul