I took off my peep sight about a year and 1/2 ago. When I first installed it I shot 2" groups. During the following weeks I shot somewhat inconsistently. I realized that I needed to fine tune the adjustments, because I was trying to anchor "to" the no-peep instead of anchoring and adjusting the no-peep to me...if that makes any sense?
It is far easier to make adjustments with the help of someone else while you hold the bow.
What I did was to draw my bow and get into my comfortable anchor, with my eyes closed! Then open your eyes and check the no-peep. This is the only way I know how to accurately adjust the dern thing, but it works great after you make the adjustments this way. Repeat the process several times to be sure that you are anchoring the same way all the time, and then make any final adjustments.
I have been shooting with one for the last year and 1/2 and would not switch bach to the peep. For me there are just too many advantages to using the no-peep!