I think an interesting outcome or "take" from all this guys testing, including the test of a pistol just returned from the factory after being sent in to be "corrected", is that I do believe this guy would grab this G21 (assuming he didn't have a "proven" pampered Glock to pick) over any of the competition, including 1911s.
He is extreme and sinful in his treatment of the pistol and he is likely to never get into a situation that comes close to even one of his tests while carrying for self defense, but he KNOWS to his core that THIS pistol will work come hell or high water...and that is almost literally from his tests... and he just cannot be as sure about any other pistol out there.
P.S. I have 4 Glocks...which puts me only slightly in BillT's shadow...and that is a position with which I can feel good.
I have a Glock 17 Gen 1... was just impressed with the pistol when I first started seeing it's reviews. Had to have one even though it was 9mm and I was a firm believer in .45 ACP.
Next came a Glock 21 as soon as they became available. Very nice, but the grip was as large as I could possibly handle.
Then a Glock 23. Grip was smaller, it is small enough for 99% of my concealment needs and the .40 S&W gives up little to the .45ACP as a SD round. (Ruger LCP works in the 1% the G23 does not)
Last is a Glock 21SF. Ahhhhh...a G21 grip that fits better and a nice 13 round load of .45ACP.
The first G21 ended up donating it's frame to a Mech-Tech carbine.
I've replaced all the Glocks the Trigger Mechanism Housing with one from Lone Wolf that allows trigger over travel to be adjusted.
I've stoned all the bearing surfaces involved in the trigger pull (a procedure performed and described here by Badgersmilk), and am able to set up a 2.5# target trigger pull up to a 5# SD trigger pull in maybe 5 minutes by replacing the Connector and/or Trigger Spring.
The trigger pull is smooth and even and after "slack" takeup, is comparable to a 1911s...just a wee bit longer.