I have a couple KCI and they run fine but yes, why buy those when Magpuls are right there $$ wise.
Still letting the Magpuls go a minute though. I just don't have the 100% confidence in them since their initial release that had issues.
Maybe im just paranoid. Then again, I have several 19 mags that need to go back to Glock as they have reached their usable service life and now have feeding issues. So, I suppose my worries are not really warranted.
I have a dozen in the packaging and 3 out that I use a lot. Basically extended personal testing. I've tried keeping them fully loaded in my range bag, to simulate a carry mag, done mag dumps, bowling pin and steel shoots. Never a hiccup, but I didn't buy any until the problems were fixed.
I did buy 5 factory 19 mags at a GSSF shoot for $10 each, but that kinda thing doesn't present itself very often.
They are noticeably lighter than the factory mags and only have one witness hole. The feedlips are plastic, so there's a potential for problems I guess, but I'm comfortable with them at this point.