I have a bag full of Q-Cs that haven't worked well over time. Brass seems to be worst at being leakfree over time, plastic--well, works nearly as well and cheaper. I have come across plastic with a 'brass'-look finish that are really cheesy and don't last.
Right now, I have my Anderson valve and flush valves manifolded together fed with a plastic Q-C that has lasted for 6 months without leaking...
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