On Sat, 31 Oct 2015 09:03:12 -0700 (PDT), TimR
wrote:

On Friday, October 30, 2015 at 12:19:43 PM UTC-4, wrote:
On Fri, 30 Oct 2015 08:23:04 -0700 (PDT), TimR
wrote:

On Friday, October 30, 2015 at 11:12:08 AM UTC-4, wrote:
I wasn't familiar with Alumiconns until you mentioned them. They look really secure, much like the chocolate blocks we used in Europe where wire nuts are prohibited. So thanks.

Is there something similar for copper?

You could use alumicons for copper if you were rich since they are
listed for aluminum and copper but why would you?

A wire nut is about 9 cents (US) while the Alumiconn is $2.77 at Home Depot.

But the average homeowner isn't going to need more than a couple a year, and isn't going to use wire nuts enough to be sure of getting a good connection, maybe. It might be worth $2.68 extra for piece of mind.

Maybe homeowners should just be calling an electrician if the cost of
"piece of mind" is not an issue.

There are literally billions of wire nuts working satisfactorily here.

I haven't had a wire nut connection go bad personally, but I have seen some.

I've not used an Alumiconn. So just wondering, if space is limited, would it be easier to fit them into a crowded box?

Short answer, no.

This really comes down to workmanship. A properly made up wire nut
splice will last forever but if you get one of the wires a bit short
and it does not engage the spring, you will have a bad connection.
For your average homeowner, I suggest stripping about an inch of wire,
twisting them up tightly (clockwise), cutting off all but the last
5/8" or so, looking it over carefully to be sure it is uniform, then
screwing on the wire nut.
The listing does allow the wires to be put in the nut without twisting
but it is way too easy to have one not being seated right for someone
who doesn't do it all day.