They are only good for really small stuff. Notice what they are soldering in the commercial /forums/images/graemlins/smile.gif
I am also not sure if I would like to solder on electronics with them as they put current thru the item being soldered.
Garbage... A buddy had one melt down on it's trial run. Smallish speaker wire. The batteries got so hot they leaked acid afterward.
Those folks in the commericals must have numb fingers as the tip doesn't cool down as fast as they show.
They can only solder like 18awg wire max.. and aren't any good on solder thicker than angle hair pasta. Besides.. like another poster says.. they run power thru 2 sides of the tip.. I'm not so sure how an ESD sensitive component might like the higher potential being generated on one of its legs.. etc.