I don't know about televisions, but on many items they negotiate longer warranties with the manufacturer. That itself can be worth a lot. For instance I know if you buy a refrigerator on their branded credit card from them you get something like 3 years parts and labor, which is often 3 times longer than the warranty from other places.
That said - it's hard to beat BHPhoto - another trusted brand for electronics and photography specifically.
Costco has 90 day returns, hard to beat.
BH doesn't charge sales tax (via Payboo card) and has 30 days returns.
On $2K TV it is ~$200 savings.
If my OLED TV stops working randomly after a year it's going to be a lot more for the repair.
Even better when you have their card. I bought my TV through them and using their card. The additional warranty gives me a total of 5 years.