we had some guys come in to a work site of mine a couple of years ago.
they had to rework a few thousand motherboards. changing one surface mount resistor for another.
(horrible job. glad we got those guys in to do it.)
now i know this was surface mount not through hole but still worth mentioning.
so the setup they used was a standard high quality soldering iron and regular solder. (i was so impressed with the soldering iron i now own one. one of the Wellar units with separate PSU.)
it was the bench they brought with them that allowed them to work quickly. it was like a draught man's table with horizontal rails to hold multiple PCBs. they then had one of those big angle poised magnifying glasses combined with a lamp (http://smtinspection.com/images/ml3000.jpg
) which ran on rails down the length of the table. their chairs likewise ran on casters the length of the table.
they would position about 12 MOBOs on the table then start at one end slide chair and lamp/magnifier down from one MOBO to the next.
they were turning out a table full in under 3 mins including racking and unracking the boards if i remember correctly.
the point i'm making, it appears from this that the ergonomic setup (light, magnification and seating position) saves more time than the tools.
obviously you couldn't mimic this exact setup as with through hole components you need access to both sides of the board but it was a valuable lesson to me about how much easier you can make your work if you prepare you workspace.