Soldered VS ...everything else

I have tried several combinations of various speaker cable bananas and there are many really good brands available that don't use solder.
With that said I have had a lot a really good success using KLE Innovations Bananas and WBT Silver solder. The bananas don't look like there is much to them, however, after break-in they sound excellent. There is also an advantage using them if needed, one banana can lock into a second banana (bi-wire).
https://www.partsconnexion.com/kle-innovations-banana-plug.html
https://kleinnovations.com/kle-innovations-klei-products/klei-harmony-banana/klei-classic-harmony-ba...
I was not able to locate the Audiogon forum but there is a bit written about them.

How do people feel about set screws in bananas or spades?

Initially fine, then degradation sets in over time.

• bare cleaned wire (literally cleaned to de-oxidize/prep)
  
• metal sleeve over wire
• crimp, hard
• solder as filler in areas of the crimp still exposed to air
  
• screw down this connection in spade/banana proper.

That’s one way to do it, and it is a way to do it that might last 20-30-40 years and need a bit of cleaning every now and then, if done with good mechanically and electrically connectors and the right metallic interfaces.

EG, neutrik speak-on connectors are supplied this way, parts wise.... and they expect you to commit to something similar to the above scenario. Users of speak-ons will do many times do this... but very few do the solder fill bit.

If your wire is inexpensive per foot, clean off about 2 inches or so of bare wire strands, then twist them so they are tightly packed and contacting each other, tie one end down and stretch out the other, solder soak that section that has wire to wire strand contact, then cut the excess end off, and have this stretch bit of solder and self-contacted strands (no wider than the original strands/set)....then insert the bulk soldered bit into the connector and screw that down. Just another way of doing it.

How do people feel about set screws in bananas or spades?

Not by themselves, again, in a gold plated copper crimp sleeve is ideal.
However, again the issue is that in the cheapest types the threads are too coarse and the material is too hard to set properly. I've seen lots of cheap examples that come loose very quickly.

As a challenged audiophile, if solder is not good then why when I had to replace a tweeter on my old Infinity Kappa 8's the connecting wires were attached with solder? Curious as what the high end speakers use to make the connection.