I have only fired a few rounds at 20 yards since putting on the williams sight, but feel that it is an improvement. I won't really know until I get out of town to shoot at a friends rifle range.
In general I find it easier to shoot a rifle with a peep sight than with the standard open sight. This is because with a peep sight your eye only needs to focus on two points as opposed to three.
The williams sight is inexpensive so try it out. I bought mine for approx $20 from cheaper than dirt.