Just a few thoughts from someone unfamiliar with Glocks...

I'll not criticize Glock advocates. If they feel comfortable with these guns, that's fine. As for after-market gadgets, they're usually for the gadgeteers who can't bring themselves to use anything out-of-the-box. It seems another gun would be better for them than re-designing the original.

Was the Glock design an attempt to improve upon the perceived disadvantage of the first shot double-action trigger pull of conventional double-action pistols? I think I may have read this thirty or more years ago when Glocks began to see regular use, but what I recall may not be correct.

I've never seen a disadvantage to traditional double-action. I'm very used to them and comfortable with such a setup. They're very safe and while some prefer a holster for carry, these guns don't require a holster for safety.

Again, it's all in what a person is familiar and comfortable with. It appears that Glocks have an excellent reputation, but we're all glad to have choices.