Hi guys, I actually make radiators for a living (aluminium)
It's a simple technology, air passing over the fins, water passing through the tubes.
Chinese radiators dont look as good as hand made radiators by quality fabricators, but they do work.
Materials may not be as good, tank folding or tank welding may not be up to scratch and general fitment problems... You do pay for what you get.
I'm running a chinese radiator core with my own hand folded and welded tanks.. works good.