I refer to the Glock, and not necessarily derisively so, as the lowest common denominator of service automatics.

And that's not really an insult

It's not intended to be. It's like the Ford Crown Vic of duty guns.

It's really heavy, old, and needs to be replaced but everyone just loves it?

Wouldn't it be more like the Honda Civic of pistols? Simple, reliable, no frills, and plentiful?

So does that make the 1911 the Ford Mustang?

I think the M1911 is more like the Crown Vic, a timeless design that everyone keeps using simply because they can't imagine using anything else and no one else makes anything like it.

That works too, I was going with Crown Vic to continue the police analogy.

It's simple, reliable, inexpensive, and everybody can drive it.

Your higher end service pistol, Beretta and H&Ks, and 1911s would be lik the old Ford Interceptors I suppose.

One could uncharitably refer to the 1911/Crown Vic as "outdated but effective".
It's hard to draw parallels between guns and cars, carrying a 100 year old handgun (design) is a sensible choice, driving a 100 year old car every day is... let's say 'eccentric'. And we've only been making cars for 120 years, how long have we been making guns? 500 at least?

Oh, Glocks. 18C. Yes I know it's silly and useless, I just like full auto pistols for some reason. And you can put it on single, then it's a 17C.

Who doesn't like full auto pistols? They are fun to shoot.