Originally Posted by duggy
i'm sure if their polymer frames can withstand the abuse the night sights can.
The night sights are steel.
Glock also offers steel fixed sights but I think you have to order them (they did come on the Austrian proofed G19s of Obamamania though).
Every police officer I know has night sights on their pistol, so I'm not sure how many carry with the plastic sights. If you look at people who shoot a lot (and I mean thousands of rounds) like Hickock45, if they aren't having problems with the plastic sights, you probably won't either. I think the strength of the mounting on the slide is as if not more important than the strength of the sights themselves.
Glock wouldn't use the sights they do if they weren't durable, durability is essential to their brand's reputation, you'll be fine, but you should get factory night sights anyways.