The US mil contract for Beretta's was not won on merit. The sweet deal that Beretta offered the gov't and some dirty dealings sealed that deal. If you do a little research the US Army demanded a pistol with second strike capability. A feature that is completely f*cking useless but nevertheless that was their criteria. That alone made the Glock a non contender. SIG won the trials with little issue. The initial contract in 1985 was for 320,000 pistols to be manufactured at the new Accokeek Maryland facility. The fact that the Marines ignored the pistol, and anyone with the opportunity to run something else did. Tends to fly in the face of what being "awarded" the contract implies.
As far as .40cal Glocks go. I would never buy one. I would never buy a 40 in the first place. The perceived "stopping power" advantage of the 40 over anything else is simply that, perceived. An increase in energy with the use of basic physics equations and a little trial and error looks good on paper. It does not however translate into increased skill no matter how you cut the numbers. Its not about what you shoot, its about where you shoot.
The only 40 cal gun I would run with confidence of not having a catastrophic failure somewhere in its life, would be the new SIG series pistols with the single piece machined slides. The 40 cal Glocks are known for having problems, CPS has apparently traded in many of theirs as well due to failures. Then again, when Glock beats Smith & Wesson to production of a 40 cal pistol for which they designed the cartridge. Its no wonder it isn't as reliable as the rest of the herd.
NAA has had zero issues with his Glock 22 and he's put a good number through it. Did he get a lucky one, or is his better built than many of the earlier copies of which so many horror stories were born. I don't know.
As was posted above, all mechanical devices fail, even knives and pry bars and they have zero moving parts(fixed blade knives I mean). The ability to use and abuse a tool for a significant period of time before failure is what earns merit. Simplicity and ease of use are often viewed as just as important. Any product that can excel in all three areas is sure to be a success.
Firearms are tools, they break. Some more often than others, buy a new one.
TDC