I once built a set of window grilles and security doors on site using one of these- and I would say our definition of "thick metal" must be different. It takes a fair amount of human power to punch a 1/4" hole with a punch like this. It may be technically a 20 ton press, and, technically, you may be able to punch a 1/2" hole in 1/2" plate, but you wouldnt wanna do it more than a time or two.
And it does leave a burr on the back of the plate- you would still need to debur.
If you have a decent drill press, that goes down to 100 or 150 rpm, there is no way this is faster than drilling, in anything over 1/4".
Its pretty fussy to locate holes- you need to layout your holes, then center punch em first, then take the handle off, delicately locate the center punch on the pointy part of the punch, then hold it in place while reattaching the handle. Then you usually need to detach the handle again to get it out.
I suppose if you built this into a very stout metal workbench, which was bolted to a concrete floor, and had fixed infeed and outfeed tables, you could get pretty quick at production punching of, say 1/4" flat bar.
Or, if you need a couple of holes, once a month.
But this is a tool designed for 100 years ago, when labor was a nickel an hour.
Of course, it depends on your budget, your expectations, and the job.
But its no miracle cure.
I have 3 or 4 hand punches like these, 25 bucks or so each at garage sales, and they are cool.
But any serious hole making will go much faster on a drill press, much less an ironworker.
I would put the ironworker price ratio much higher, actually- I can usually find a #20 for fifty bucks or so, but a decent used ironworker is more like ten grand. And worth every penny.
I am used to projects, though, where I need to punch a hundred holes in 1/2" 304 SS, and want it done in an hour.
YMMV.
If I was you, I would be looking for a used mechanical ironworker, a mubea or geka or peddinghaus, often you can find a 40 or 50 ton for 3 to 5 grand. Dont pass Osha inspections, but they put a big smile on your face when you use them, versus the sore back you will get after ten minutes of a #20.