The LG ##LH90 does have LED backlighting and LD. The LH is 4-1/5" thick. The ##LHX (Wireless Media Box) is 1.5" thick.
The big addition with the LH90 series is LED backlighting with local dimming. This LCD-based TV employs groups of LEDs (as opposed to the standard fluorescent lamps behind most LCD screens) that can be individually dimmed or even switched off in different areas of the screen. The system is different from edge-lit LED-based LCDs, such as the 6000, 7000, and 8000 series sold by Samsung, because the LG's LEDs are arranged behind the screen as opposed to, well, along the edges. In general we've observed improved contrast, along with some tradeoffs, with local-dimming technology
Samsung 78JS9500,Parasound Halo JC1's, Sonus Faber Olympica III, Marantz AVR8802A, Oppo 203 & Sonica DAC, (2) SVS SB16 Ultra's
(For Sale) Parasound HCA-3500 dual monoblock chassis [500w X 2 @ 4Ω]