RE: What size of peep?
I think it's a matter of personal opinion for the most part, whether or not you use a kisser or not, angle of string, etc, personally like a 3/16, but for target shooting, a 1/8 can make a guy deadly as well. But a 1/8 is too difficult to see out of for hunting at low light. I learned that the hard way. If my peep won't match the pin housing when I look through it, I'm instantly thrown off, and likely to make a bad shot, therefore, I'm still in the stone-age of tubed peeps.