Uhm, no. A "LED" TV is still a LCD TV. The only difference is the backlight source.
For full LED backlight, the difference from old-style can be quite big through making dynamic contrast being an actual advantage, instead of a liability. With edge LED, which 90% "LED" TVs has, it's not completely the same backlight-bleeding, no-blacks junk, but not that far off.
When/if we see real OLED TVs, it will probably be another matter. Until then black levels, contrast, screen update (do NOT get me started on "100/200/400 Hz technology") and general quality are all completely in the hands of plasmas.
Only advantages for LCDs are brightness/anti-glare (if you have a really bright living room, or strong lightsources in front of the screen) and power usage, and maybe small-screen resolution, but 1080 on a 30" set is a joke anyway (unless you sit 1 meter from the screen). Burn-in is a non-issue in modern plasmas.