I have only put a few hundred rounds through my centerported 9L with the Dawson FO (front and rear) and have had no problems. And they do not get as dirty nearly as quickly as the standard iron white sites the gun came with. The fiber optic may dull slightly until cleaned, but because the fiber optic is more flush mounted (surfaced), it can be easily wiped at the range where as the indented white iron sites need a q-tip and even then, without cleaner, your white site becomes grey blending in with the rest of the black site within 25-50 rounds. So I would say the investment in the Dawson FO was well worth it. Even if the front optic eventually breaks, they ship with plenty of extra fiber optic if replacement is ever needed and more could be purchase as well.