Gave the Williams peep on my CZ Ultralux a good work-out on Saturday and I think I am getting the hang of sighting it now. You do need to adjust it up and down several clicks based on yardage, but once you figure out what works for you it becomes pretty decent to shoot with; I like that you can use the stock front blade and sight it to see target rather than cover target.
Here is 20 rounds at 100m using Federal Match Target - the target is a 25m pistol target (so the black part is 6" round). The first ten I had only one flyer. Next ten added a few more (then my friend popped some 7.62 into it before I took the pic). Anyways, the Williams sight shows potential if you adjust it accordingly.
