Never met anyone except online who had problems (breakages, mechanical malfs., etc.) with their glock. If they did, it was usually due to them messing about with it, like adding aftermarket springs, etc. Not saying it doesn't happen of course, just saying that there aren't many problems that exist independently a user cause.
My 17 has had around 15,000 rnds and has not had a malfunction or breakage, and the only signs of age are from holster wear. My 33 hasn't either, but it's only had around 7,000 rnds through it.