Agree 100%, I've had to replace trigger bars in my Gen 3 19 and all my Gen 4's. The plating usually starts to bubble and the trigger pull will progressively get worse until it's just too nasty to use.
I have a G17.5 that has a little over 500 rounds and feels just like it did after the initial application of grease. I recently picked up a G34.5 and I can tell the difference in pull due to the different connector. Between the two I like the G34.5 break better.
I'm eventually going to send off trigger bars and connectors to have them coated.