RE: No-Peep
I use a no-peep alone without a peep on the string. Things I don't like about it include having to look around the string instead of through, and not cheating by moving your head, or adjusting your grip in order to get things to line up instead of adjusting your anchor (it's easy to do).
That said there are too many good things about it to ever go back to a peep. After using it for a few years, I tried to put a peep back on along with the no-peep. Needless to say I didn't like it.