[JRTJH]

We tried that "technology" in the Air Force 20 years ago. The problem we had then (and I'd suspect now) is the inability to determine whether you have a cold solder joint, if there's proper seating of the two wires in the solder bed and whether the solder fully engulfed the wire at the solder joint.

We eventually went back and replaced every one of them with "tried and true" tinning, soldering and shrink tubing installation.

Like chuckster said, some work, some don't... I'd suspect it's as much a "technician technique" as it is a "materials deficiency"...

I prefer the old "tin, solder, insulate" process.... Honestly, for as little as most of us make wire connections, using a "shortcut that might not work" is really not much of a "time saver" as it is a "novelty approach"....

Now, if I was making 1000 connections a day, I'd look for every process that might save a few seconds. That said, chances are very good that by installing that many on a daily basis, I'd develop a "never fail technique"... But, installing 2 this week and 2 more next year ??? I'd be concerned with "technician issues".....

JMHO, but I wouldn't use them.