Why have I seen Holosun talked about on Airsoft forums? Airsoft is like any any other shooting sport, participants want to have whatever competitive advantage they can afford.  Holosun offers high quality, reasonably priced optics that give that advantage. While Holosun optics are designed for firearms, they have performed well in Airsoft competitions.   Also, people are now finding the recoil from gas blow back airsoft rifles is enough to destroy replica Airsoft optics.  Holosun optics don't have this issue.