Using the push-in option (and no screw tighten) on outlets

Uh, no, my basement is already wired and I used the screw terminals.

If you are collecting data my personal experience is do not use push in ever.

Yep, In the last house I lived the wife always used the same receptacle to plug the vacuum into. I plugged something in one day and a heard what sounded like a spark/sizzle sound. Pulled the cover plate and receptacle too find burn marks at one wire on the back stab.

UL listing means exactly what it says on the listing and labeling. It complies with the standard that applies to that labeling. UL does not write the standard they just test to the standard. If the standard is inadequate don't blame UL.

-- Tom Horne

???They are UL standards developed by or under the leadership of UL. UL lab's reputation depends on the effectiveness of the UL standards.

Some standards may not determine if a device actually works. A lot do - fuses, GFCIs. IIRC receptacle tests include 150% of rated current. Receptacles should 'actually work' - except for the backstab feature. I can't understand how that is allowed by the standard. Other than backstabs receptacles are pretty reliable.

In addition to contact area, another problem is contact pressure.

I've only had problems with stab connections on a house with aluminum wiring. The wire is so soft that the spring eventually mashes the wire so flat that good contact is lost. In houses with copper wire it's never been a problem. That said, when I replace an outlet when a tenant breaks one or paints over it, I use the screws.

Backstabs were never approved for and never should have been used with aluminum wire. IMHO dangerous.

Still have a house with aluminum branch circuit wiring?

Yeah, but it happened. A guy who worked with my father asked me to look at an outlet in his house that was not working properly. Some of the plastic was actually charred. It was fed with aluminum wire plugged into a backstab port. He's lucky it didn't get a little bit hotter and start something burning. I think I told him to check all the outlets in the house for the same problem (I was still in my teens at the time, which is a long time ago now).

My own house has copper branch circuit wiring and backstab-connected outlets and switches. I haven't found any problems I can attribute to them, but whenever I'm working on a switch or outlet for any reason, I'll switch to using the screw connections because I just don't trust the backstab ones. Or I'll junk the existing switch/receptacle and replace it with one that has rear-entry screw clamp connections, which I like better than the side screws.

Dave