Ok, I have fired Glocks, and no since I don‘t own one, I can‘t comment on it‘s ability to take abuse.
From everything I‘ve read, it is a simple tool, easy to use, clean, and maintain, has a good size capacity, and is quite durable.
If I ever did own one, of course, I wouldn‘t be burying it in sand or whatever to test it. However, I‘ve heard from people who have played with them that it DOES fire under water, it will put up with relentless abuse, etc. It has loose tolerances, however, and is not a match target weapon. I wouldn‘t recommend it for IPSC, then, but clearly this kind of accuracy isn‘t needed in a military sidearm.
No, I am not a Glock saleman.
Personally, I‘d pick the H&K USP40, like the one I own, or the USSOCOM cousin. However, at the end of the day, when you really need a sidearm, you are in the **** anyway, and I am sure you just want one that works.