I have an M&P9 and an SR22 both with RailMasters. They are not useful in medium to bright light outdoor settings. OTOH, I have not found an indoor situation (up to 25 yds) with any kind of lighting where I didn't prefer the laser visibility to iron sights. And in near total darkness, the laser is superior to any IMO.

So with my old eyes, the laser + iron sights of any kind cover all situations for me . . . except a dead battery lol.