I am currently shooting with both a peep sight and a kisser button. But I got thinking about this, isn't that kind of redundant? I know I will gain a little speed by removing one or both, but I am not really worried about that, as my Hoyt is like, well, like the best bow you can buy...
Anyway, do I need both, or will a kisser button only be just as good?

Thats an individual decision. I dont need both but by using both I achieve my best groups , especially when I'm using a loop. When I'm using a loop my release hand sits back too far to use as a consistant anchor point on my face so the kisser helps keep my anchor point consistant. When I'm shooting off the string I can ditch the kisser button and get a consistant anchor with my release hand on my jaw. Same with the peep. If you shoot better with it then keep it. If you shoot just as good without it then ditch it.

you dont have to use either one for that matter but it makes it a lot easier to locate youre anchor point with either one or the other. I use a peep without a kisser.

You don't need both. If you shoot 3D or spots, I would go with a peep but for hunting, a kisser without a peep, gives you some advantages that last 1/2 hour before dark. I shoot up to 30 or 40 yards as well with a kisser as with a peep. If you are just trying to get speed, I would just put a 1/2 turn on your limbs as the gain won't make or break you. Speed kills only if you hit what your aiming at. Don