Sony X74L or Bravia 2 is enough for most people. IMO Bravia 3 or Samsung Q60D or LG QNED80 doesn't justify the price premium over Bravia 2.
Only panels which is a worthwhile upgrade over normal LCD panels is FALD LCD or OLEDs. Companies just crank up brightness from say 350nits to 450nits (maybe even a better DCI P3 coverage) & try to charge a premium, IMO waste of money for most as it is still not a true HDR panel.