Yeah... KISS my you know what!
Just kidding. But seriously, there are so many more Glock proponents out there than H&K simply because a lot of people can't afford the more expensive gun. Or maybe I should say they don't want to spend $750 on a gun when they can get a decent alternative for $500.
If you want my opinion check out this thread I just made the other day:
http://www.thehighroad.org/showthread.php?t=425714
I've owned them both and can say get the H&K with confidence.
For what it's worth, the H&K can be converted to the LEM trigger, which screams "Keep it simple, stupid!" It behaves very similarly to a Glock trigger, except I like it better because you can verify the hammer isn't moving when you holster your weapon. Considering the Glock trigger safety is a joke, I think the LEM trigger system is a better and safer approach to "KISS."
I don't care what anyone says, if you have small-medium hands you will love the feel of the USPc over the Glock 19.
The point is, the H&K costs more for a reason. The Glock is still a FINE firearm. I'm not bashing it in any way because it still does what it's supposed to do. Hell, I've owned three of them and still have a glock 26. However, IMHO, H&K makes a superior polymer handgun.
If money is tight, go with a Glock. But make sure you shoot both before you decide.