Not to be argumentative but that's where the operator comes in. You can get a good quality joint from a basic radio shack pencil. Even more likely with a Weller. That's where the operator comes in, you have to be able to recognize a cold solder and redo it or give it a few seconds to reach temp again/sponge off. No matter how good a tool, the operator has to be smarter than the tool. Period.

