4K led uhd tv's

[VX L67 Getrag]

Just wondering who out there has good knowledge/experience with tv's.

I know with the plasma's it was all about refresh rate & Hz... But not sure about the led's, it seems there's a big price difference between them all & Kogan are half the price of main big brands but I was under the impression they just choose best quality for price range & use main brand equipment & rebadge to theirs?

What's best for value as I'm thinking about replacing 68" Samsung 3D I think series 6.5, which just has some weird discolouration around edges but only on white/light color images.