It's frustrating when some people put out false information about quality products. The Kadee industrial plastic couplers and pockets are rock solid when properly installed. My experience:
For reliable hands off coupling and uncoupling of cars on my coal branch I found I needed to standardize the couplers on my hopper car fleet (90 cars, 10 different makes, plastic, die cast, brass). In fairly extensive layout testing I found that the 8xx series couplers coupled and uncoupled better over magnets on curving mine sidings sidings than the newer (better looking) 7xx series couplers. The extra inter knuckle "slack" also facilitates uncoupling with a pick in areas without magnets. I standardized on the plastic 804's over the metal 805's as they provide 2 rail insulating properties for brass cars with metal trucks. An added plus is that the freight car color 804 draft gear blends well with PRR red car bodies (someday they'll get weathered). All the hoppers weight at least one pound, and I've had zero issues with broken couplers running 35 car coal drags on 2.2% grades.
