Hmm, massive cost difference between the orange so called POS and the Metcal though, I wonder if the POS could do that with the bolt? Possibly could if it has the right size of tip with some thermal mass to it, who knows?
What gives me confidence with the Metcals is that I know the immutable laws of physics mean that the tip
cannot get too hot. It will not exceed the set temperature for that tip, even if the electronics go crazy. So as long as I've chosen a tip from an appropriate temperature range I can't burn a board, even on a tiny joint. Then, the ramp up of heat delivery is so fast that the same tip will handle a joint with big heat requirements. I'm not going to be in the situation that conventional irons can put you in, of having to use a tip with lots of thermal mass and high temperatures to get a difficult job done. Solder to a ground plane with a Metcal and it
will not burn the board, no matter how long you leave it there - do it with an iron that needs a big tip with the temperature turned up to solder to a ground plane and hang around too long and the board is toast.
I find that I tend to keep the same mid-sized tip on the Metcal all the time (an SSC-637A, 30º chisel tip, 0.070", 357ºC) and with that I'll solder everything through hole from the smallest parts up to 4mm binding posts. I only swap to a physically smaller tip for SMD stuff. I've got a bigger tip, but I haven't had to break it out yet.
I'm constantly amazed that my Metcal is only 40W. It will do the work of a conventional iron with a much higher rating. The fact that the heat delivery is strictly confined to the actual tip, not to a larger heater that then has to get the heat across to the actual tip, makes it capable of delivering as much working heat as a larger iron, but without the time lapse associated with all that other stuff to heat up. It pisses all over the 65W temperature controlled Antex that I was using immediately before I got the Metcal. I still have the Antex, it hasn't even been turned on since I got the Metcal.
Mine was £70 off eBay, so you don't have to go cash crazy to get one.