I have a hard time believing a change in backlight would make for a 'it's as if I was there' experience. No TV really offers that.
LED TVs are just LCDs with LED backlighting, nothing else. It's a blatant dishonesty on the marketing front. True LEDs are OLEDs, and those are not mature enough to take frontstage in the market yet.
There are distinct differences between the technologies, and I'm sure you already know some.
Plasmas have the ability to produce higher contrast and deeper blacks because they don't require a true backlight.
Plasmas alias better, so they produce 720p content when upscaled to a 1080p resolution panel.
Plasmas are heavier, get hotter, and consume more energy. More expensive in the long run but cheaper on the short run.
LED backlit LCDs consume less energy than CCFL LCDs, usually have more vivid colors, and full LED array backlit LCDs (expensive) can dim certain areas of the screen to provide more contrast and better blacks. Some cheaper LED backlights have backlighting inconsistency.