wandering
The post seems to be wandering from "1911 on duty" to single stack v. high capacity, which is not quite the same thing, but I'll offer some comments, then try and come back to center.
While I did not carry a 1911, I "walked beside" (an old Skeeter Skelton phrase) a single stack SIG .45 for quite a few years on a daily basis, as the P220 was one of the approved duty guns for my agency. As such, rarely, did anybody who did so in uniform, back it with just two 7 rd mags. As soon as the reliable MecGar 8rd unit hit the field, they went to work, typically carried in a quad pouch. That's 41 rds counting the ammo in the pistol. The equal of a G21 backed with 2 hi caps. And very close to a G22 with 2 hi caps.
While the modern poly pistol is very reliable, implying that the 1911 will not hold up under abuse, when "everybody gets one" is flawed logic. It's hard to dispute the record of the 1911 durability/reliability wise, or it's wide spread issuance, over two World Wars, Korea, Vietnam, and other bush wars fought by all branches of service. By comparison, the Beretta's (not polymer I know) record is not near as strong.
"Sweeping" suspects and other officers/non threats, is not a trigger pull weight issue, but a training issue. Muzzle integrity and finger placement are issues no matter the system. By comparison, the police shotgun, and the patrol carbine, are both "SA" systems, with external safeties, and muzzle/finger applies to them as with any firearm.
The DA/SA systems are not without fault. The transition from DA to SA is real, though can be overcome with practice. But move away from the system for awhile, and the issue will surface. I shot my SIG, cold, recently at a match, after shooting Glocks for about a year and double/single gave me fits. Finally, I have seen some people fail to decock the double/single pistols, either under stress, or from stupidity, when they really should have. Which is why I think I'm finding the Glock pistol, or maybe better , the XD with its grip safety, more and more interesting. Same pull, every time. Which can be said of the 1911 BTW.
Lastly, I think the big bullet arguement still is a good one, despite the FBI's recent re-endorsement of the 9mm. I will not elaborate as it's been hashed many times. But as a "patrol" caliber, where obstacles, cover, etc, are commonly encountered, that big chunk of lead has some merit. Many gunfight wounds are from fragments, and the bigger fragment the better.
BAck to post. You occasionally see a 1911 pistol in LE here in my area, but it is typically not a uniform/duty gun. Just last weekend I crossed paths with a Co. DTF officer, whose carry gun was 1911. There are also some high speed low drag types in the the PD across the river (75-100 officers?), Invg's with collateral SWAT assignment, who carry it as well.