I am currently taking a firearms instructor training class for my job.
This class consists of a mixed group of criminal investigators and LE personnel from various state, local, and federal agencies. All the attendees are basically good shooters who know how to run pistols AND who were picked by their boss to become firearms instructors.
The ammo used over the two week course was about 800 rounds per shooter, all of it Speer frangible. That's fairly dirty ammo, but whatever, we didn't shoot them that much.
The pistols:
10 Glocks, mostly 22'x and 23's, one G17.
12 Sigs, 2-220's, 1 239, the rest 229's in 40 and 357 Sig.
1 Beretta M92, 1 XD in 45 Auto
None of these pistols were particulary beat or abused.
The failures:
The Glocks, Beretta, and XD: 0 failures.
The Sigs:
2 - 229's that broke extractors
1 - 229 where the weld on the take down latch (flat piece of metal) somehow sheered from the semi-circular locking bar that runs across the frame, allowing the latch to just spin freely and requiring a Sig armourer to do some magic ju-ju to dssy the gun and fix it.
1 - 229 that suddenly just failed to feed multiple rounds until an instructor more or less beat it into battery. Then it seemed to run fine.
These last two failures were described to me by fellow students, I did not see them myself.
I own several Glocks, but I also like Sigs. I am not posting here to diss on Sigs or start some "my gun better than your gun" Jihad. But four failures out of twelve guns is ridiculous.
What is the deal on Sig's current QC? A lot of the folks in my class expressed concern after seeing these failures on the Sigs with no failures on the other guns.