I've lived in Europe where wire nuts are prohibited, and always thought a screw terminal, chocolate block, etc., was probably more secure.

Today I experimented, wiring a new light in my shed and using Alumiconns instead of wire nuts.

Well, they work. They're very secure. they cost $3.50 each instead of 9 cents. They don't save any space in the box; actually they take more, because they have to be oriented to not interfere. And while on the bench they look dead easy to install, up on a ladder inside a ceiling box it was a different story. I had a heck of a time getting everything lined up just right with stiff solid wire that had to be stripped to precisely 5/16 inch. It took at least 5 times as long as to wire nut them, maybe more. Of course you'd get faster with practice. But I don't think anyone could afford to lose that much time in a production setting.

I vaguely remembered the box was missing a cover. So of course the one I bought didn't fit.