Do you all call the "heat shrink butt connectors" "Scotch Locks" down there? Ours are gel filled, slide your two wires (or more for the fancier ones) up into them and squeeze the button on the Scotch Lock to connect the two wires and seal them in the gel.
They do work very well here (our version of them).
Couple thoughts: solder penetration looks reasonable for small AWG wire sizes and melt temperature must be low to avoid melting through the plastic overlay also as evidenced by pushing around the solder pool with a fingertip. Also attempting to keep the splice together with whatever is attached on both sides while rotating to melt/shrink the connector is likely to be a fun endeavor. I'll have to say thanks but no thanks; like 'Dreamin', I'll keep soldering and heatshrinking.
These scotchlok connectors were a great invention when they first came available when you were fixing up your wiring from your car to your trailer light connections, but as you can see the lack of sealing from moisture as David said "never seem to be reliable long term".
The silicon filled ones are what our 'Tel$tra' use over here in the pits to fix up our phone lines, and the silicon seals moisture out, but these are then put away and they get no further movement in the pits afterwards.
I like them because you can make an in-situ repair during the middle of our lights seasons.
The heat shrink with the low temp solder is what I use here, but I also put a larger sheath of heatshrink over the top of them, as I believe it reduces stress around the joins, and therefore more reliable long term connection.
Nothing will beat a properly soldered connection with heatshrink sealing them off, and whilst I've done that many times myself, it is fiddly.
Ultimately, it is up to the end user how they join together their lights, but real soldering is still the best if done properly.
scotch locks are the ones that algerdes posted photo of. I agree the other clamp type not suitable. Good to know that someone has used it and it works for quick repair.
Cheers
Original Scotch-Locks (here they were spelled Scotch-Loks) did NOT have the gel, but worked until rust caused some "interesting" troubleshooting for outside-plant personnel. Once they put the gel into them, they became the "goto" for doing inline patches. I prefer to solder and heat shrink tube (with adhesive lining), but in a pinch and in a hurry, the Scotch-Locks are great. I've been recently introduced to a new form of them, looks like a butt connector but both wires go in the same side. Blue and gel filled. Seem to work well. (Still under evaluation.)
Sorry if this takes the thread in a direction it wasn't intended to go. My bad.