I too would like to know the answer. I would elaborate on the basic question as follows:
- is there a measurable and predictable difference in lifespan of the various LED backlit LCD displays?
- how do display size and resolution affect lifespan?
- is the lifespan more appropriately measured in elapsed, powered, time or operational time?
- what is a representative, reasonable to expect, mean lifespan? (ROM - Rough Order of Magnitude)
- what is a representative spread (standard deviation) for this class of product?
- is the lifespan of this technology improving over time? if so by how much? (ROM)
Given the information above, the LED back light is not part of these numbers. However, I would expect, the LCD gates (pixels) and power supply to last longer because of the reduced heat and power drain of the LEDs