@Max...Adam said... "...a significant amount of the through-hole devices were lacking in the amount of solder required to make a good soldering joint. The important through-hole components, such as the optocoupler and the triac, seemed to have good solder connections..."
The bane of my life is poor wave-soldered connections on large or mechanical components, especially connectors or other connections to off-board components. ICs and discrete parts don't move much and are fine with minimal solder, but a connector (especially one that is used often) needs a good amount of meat on the joint. If I had a dollar for every connector I've resoldered, I could....buy you lots of beer and bacon :-)
I informed the vendor of this very issue, and the corrective action was already in place.
I have had the chance to use this device rather extensively over the 4-5 months or so, and I have specifically been looking to see if there are any issues that can be associated with the lack of quality in these solder joints. To date, I have found none.
I agree with you though Max that I also solder all joints even if they are no connects. It is just easier than missing a critical joint.