LED is solidstate backlight, I think old LCD monitors actually use funky flourescent bulb stuff for backlight, and use more power & more likely to burn out.
also check how much wattage each model TV draws...specs will usually show how much power the screen uses, and power for the speakers...you might prefer a TV that only uses 65watts insteada 100 or whatever, I have not checked so I have no idea what they average.
l8r