Here's my new baby: Glock 21 SF with Surefire x300. Got it yesterday and put 500rds through it today. Ran quals with it out of the box. Pulled four rounds from the 25 a bit low and left - scored a 92. Second time I ran it I shot 100. Rapid fire from the 7 was in the head and from the 5 double taps were in the triangle. I'm loving this weapon already. Totalled about 500rds through it today - three other guys ran a mag each as they are about to buy. Head to head with another 21 SF without the light there is a noted difference in recoil. More of a push than a snap, if you know what I mean. Followup shots were much faster than with my USP.
USP is now officially retired. I've replaced three firing pin springs and an extractor in 8yrs. Numerous mag issues, as well. We shoot the heck out of them, so they are bound to break. Hell, we had three Mp5's go down today on the range. None of my Glocks have ever failed to fire. They get about 50% of the range use the HK gets, so take it as you will.