A wire nut, When complete solid splice. When you push these in. They seem loose and spin. Catches only on a very small percent of the Mechanism inside. There will be issues im sure.
As long as contact pressure is maintained they will be fine. There are other things out there that have only a limited amount of contact surface that have seldom failures, like self piercing type connection devices.
Biggest problem with back stabbed receptacles is that contact pressure likely diminishes over time.
I have dissected both a "push-in" connector and a "back stab" on a switch. The "back stab" has little area of contact and the spring (if you want to call it that) is weak.
The "push-in" has a larger area of contact and the way it is made the spring piece keeps constant pressure on the wire. Also the way it grips the wire it digs in when you try to pull it out. It does spin but anything round will spin if contact is only one one side. Also, most of these connectors are made to re-use. The 6-port is not listed/rated for reuse. But the rest you are supposed to twist the connector while pulling to get the conductor out.
It isn't easy to get out.:happyno: Especially smaller wire. You can try a little test on one. Push a conductor in then twist while pulling until it comes out. Then look at the wire, it will have a groove or rough spot where the spring gripped it.
I would venture to say that if any fail that 97% were not pushed in all the way, 2% probably were used in the wrong application, and 1% maybe some defective ones. I had that happen (not in all the way) on one of the first that I installed. The trick is to make sure you strip the proper amount of insulation and make sure the stripped end is straight and not bent. Then make sure you push it in all the way. It is easy to see because the end is clear and you can see if the conductor goes all the way in. I've found that on #12 wire, it's easier to grasp the conductor near the end with needle nose pliers and push in with those. That lets the wire stay straighter while allowing you to use more force to insert it.
I've been using the Ideal brand and a few of the Wago brand for 3 years with zero problems. I think people that are skeptical have had, or heard of, bad experiences with back stabbed devices. Also, there were some cheapo ones that came with can lights that weren't very good. I have noticed that Halo cans now come with the Wago brand. So they probably got a ton of complaints on the cheap ones and changed to a name brand that was reliable.
