In the case I mention, the pistol could not be either re-assembled or disassembled & had to be taken out of service that night till the department armorer could get to it the next day.
Plastic does work, at least to a degree that makes it reliable enough for general sales, obviously, but...
It's not there because it's the "best" way to go, it's there because it's the cheapest way to go while still maintaining an acceptable performance rating.
Quite often a maker's definition of "acceptable" differs from mine.
If I end up keeping the 75D here, and it's looking like I probably will, the plastic guide rod will go & the trigger will be cleaned up for certain, and the mag floorplates will probably be replaced.
My only three fixable concerns with the pistol.
The narrow slide top riding inside the frame rails instead of outside it mildly impairs quick slide manipulation, but there's nothing that can really be done about that.
Denis