The most fundamental difference here is panel technology. The LG C5 uses an OLED/AMOLED panel, which delivers perfect blacks and theoretically infinite contrast by switching individual pixels off entirely. The TCL X11K uses a Mini-LED-backlit LCD (QLED), which relies on thousands of small LED zones for local dimming — capable of very high brightness, but unable to match OLED's pixel-level precision. In practice, the LG will look more cinematic in dark rooms, while the TCL may punch harder in bright environments. The trade-off is compounded by size: the TCL is a significantly larger 97.5″ screen versus the LG's 83.5″, which also explains its lower 45 ppi pixel density compared to the LG's 53 ppi — meaning the LG renders finer detail at normal viewing distances.
On refresh rate, the TCL holds a measurable edge at 144Hz versus the LG's 120Hz, which matters for fast-motion content and gaming. For HDR, both support HDR10, Dolby Vision, and HLG, but the TCL additionally supports HDR10+, giving it broader format compatibility — a real advantage for content mastered in that format. Adaptive sync coverage differs slightly: the LG adds Nvidia G-Sync support, making it more versatile for PC gamers with Nvidia GPUs, while the TCL tops out at AMD FreeSync Premium Pro. Both share identical 178° horizontal and vertical viewing angles, 10-bit color depth, and 1070 million colors.
Overall, neither TV dominates outright — the choice depends on use case. The LG OLED83C5PUA has a clear edge in contrast quality and pixel density, making it the stronger pick for cinephiles and mixed-lighting rooms. The TCL 98X11K counters with a much larger screen, a higher refresh rate, and broader HDR format support, making it compelling for sports, gaming on AMD hardware, and immersive large-room setups.