Good enough =/= as good as others.
And Samsung TV's are a good choice (albeit not THAT much cheaper than Sony's)... Sony's screens are acually theirs - developed in a joint venture with Samsung.
Are we talking about the S-LCDs here? Seems as though Samsung is the primary shareholder in that one (50% 1 share), and calls the shots. Doesn't mean Samsung cannot use them in their own TVs as much as Sony.
Maybe it's just this region, but Sony TVs have generally been A$500 to A$700 more than the two largest, and quite frankly, there is not enough difference in quality to justify that extra expense.