They should be pretty much the same since you are looking at two similarly sized sets with the same 1080 resolution. BUT...

The screens are all pretty much made in the same small number of factories in Asia. What differs between sets - other than the size of the screen - is the circuitry inside the set that puts the picture on the screen. To some extent (setting aside discount sales, etc.), you get what you pay for. Not knowing anything else about these sets, I might be inclined to think the more expensive one has a more robust power supply, more input/output choices, better quality driver boards and chips, better speakers, etc.

ah, so i should get the additional extended warranty for 3yrs? than when set dies at month 39, i have no coverage.