Hello, sir. I am not a strong fan of the polymer-frame pistols, but have owned a few Glocks and an XD9.
All of them worked fine and met expectations.
The only "plastic pistols" I currently own are a G17 and 26. Both function flawlessly and I'd trust either for "serious purposes" if required.
I don't see it as an either/or situation and enjoy both the polymer guns as well as the more traditional ones.
Speaking only for myself, the newer "plastic fantastic" pistols are not quite so enticing esthetically, but I absolutely respect their functionality.