Yeah, I'm familiar with the theory that the 9mm sucks because of the tapered case. I've read about it -- just did a refresh 'cuz of this discussion, in fact. I'm not convinced that it's anything more than an academic problem, but that's on me. Since the 1970s I've owned plenty of single stack magazine 9mm pistols and shot a lot more -- including Stars, Berettas, Colt and other 1911s, a couple of HK P7s (which I regret letting go) and a couple of S&W 39 series. Never did the tapered case/single stack mag problem arise.
My son -- bless his heart -- has an affinity for Kel-Tec designs.
His PF9 -- a single stack -- has been utterly reliable, which vexes me. I despise that gun, but it works.
But I digress.
Sorry about your luck with your agency.
I've two 43s and a 43X and a 48-ish (48 frame wif a Brownells 48 slide and a HS 407K). I like'em all. The 43s I got back when they first came out, loved it, had to have a second (which is my nature). Then came the 43x and the Shield Arms mags. Got one and a stack of mags, had to have a second -- and more mags. (So much for Glock not pursuing a better magazine, huh? lol) So far I've had no problems with any of those guns. For the record I practice/train with whatever FMJ 115 grain I can get and carry 115 grain Gold Dot or 115 grain Black Hills.
In fact, of all the Glocks ... no, make that all the pistols I've currently got, the only one that's given me fits is an early Gen 4 Glock 19. Replaced a mim firing pin (that broke) and the recalled recoil spring assembly, and it runs like a top.
Anywho, I agree that the 43x/48 is da bomb, but there's no need to abandon the 43.
You mention variables. I get that, especially with an agency. We had guys switch out parts on issued sidearms in the Army. Not a good idea. Ironically, back when I was an MP the armorer would have us all dump our parts in a bucket of cleaning solution, then fish'em out and reassemble our guns. Luckily they were so old they had enough play that they usually worked. Again, I digress.
But nowadays it's common place for shooters -- many of which are on this forum, no doubt -- switch out parts more often than they change underwear. Me, I try to standardize on my kit, most all of my Glocks have the same or similar trigger and sights/optics.
Ironically, when RDS were first being considered for social purposes rather than just games, there were all sorts of doubters and nay sayers. Everything from the weight of the optic on the slide will cause malfunctions to whattaya do when the battery dies, boy? And here we are.
I'm not trying to change
your minds -- I'm just sharing my experience so that others who bother to read this (the fools!) understand that there are options. I frankly don't care what kind of gun you have, a primo Glock, a cheapass PF9 or an old Smith and Wesson. They can be made to work.
To each their own.