Non-metal sights, specifically Glocks

[sakata8242]

I have personally witnessed the rear plastic sights get ripped out of the dovetail with only 1 or 2 one handed slide manipulation techniques. (Using the rear sight to rack the slide against a boot or belt loop)

Other than questionable long term durability and issues with fit within the dovetail, the plastic sights are at the minimum, sufficient, for range use. One plus is the sights themselves aren't susceptible to rust...

 

[Viper225]

I currently have 2 Glocks. My Match Gun which is a G35 Gen IV, and my Carry Gun which is a G23 Gen IV. My G35 has a Black rear combat sight and front Fiber Optic. I see this sight better than the factory plastic one.
My carry gun has a TFO front with a Black rear. The TFO gives me Fiber Optic for the range, and Tritium for Night Time Carry.

The factory sights will work well for a large percentage of shooters. However you do have better and more durable choices.

Bob R