On my range guns with fiber optic sights I've got .105 fronts and plain black rears with a .135 notch.
I just bought a new set of night sights for a Glock and went with a .125 front (the thinnest I could find with tritium) and a plain black rear with a .125 notch (4.25" barrel). This setup is pretty tight, much tighter than any other set I've had, but I'm interested to see how it'll work out and am gonna give it a try.
