I like a peep when shooting with a release. I use a 1/4" & bust knocks with it. I do shoot with both eyes open tho & think that makes a big difference. Someone mentioned just seeing fur in close thru the peep. If you open your other eye thats not the case.
I have a bow set up for fingers with no peep. I just find it more natural finding an anchor point shooting fingers & consistencys the key.
A peep sight more than anything else forces your head to the same position every shot. Maybe I shouldn't say forces because you should be comfortable but it helps alot to keep consistent.