You can get anywhere from three to five Korean mags for the price of one Glock mag. When you're dealing with courses that involve high round counts, this can be helpful. The work most of the time, and it's not like they completely freeze even when they stop working normally. I'm not opposed to the unplanned stoppages as training idea, either. I am considering the idea that you could take the mag bodies and substitute different springs and perhaps followers to gain reliability. When I was getting started, it was a useful thing. And not locking back on empty is not a deal-killer for me for a range-use item.
At this point, I can if desired ditch the Korean mags. I now have mags to work on mag changes and certain other manipulations with as well. That said, I'm still not opposed to the purchase of additional units. I just won't use them for EDC, that's all. That would be a true false economy.