I know this TV has known vertical banding issues, so please excuse if this has become the de facto price lately and not worth pointing out. I think one of the benefits of getting the Best Buy version is having an easier place to do exchanges if you want to play the panel lottery.
It is neither a Good nor Bad thing. It has both benefits and limitations.
The TCL subpixel dimming algorithm produces a Texture on gradient test patterns on any Non- 4:4:4 signal sources, (which is most bluray players, netflix).
On real images which have native noise, and NON uniform angled gradient, the texture blends correctly. ONLY 4:2:x source, 90 degrees gradient test patterns produce the effect which looks like banding.
TCL panel lottery is bad, you might go through 3-4, not unheard of.
You're looking for Dirty Screen Effect, and Backlight Uniformity/Bleed, Test by using a source with a flat black background, Turn Tv backlight setting all the way up, turn off eco mode, dimming, dynamic contrast,
TCL subpixel processing shows up on MOST models. This may not work well for PC use, because it does distort Thin line rendering, and can obscure certain high frequency Textures (Such as tweed-fabric Suits, which may cause flicking moire, or brush metal finishes which end up looking flat grey) For movies/ games, the algorithm is mainly beneficial, It increases contrast uniformity, sharpens slightly, increases viewing angles/ black stability.
Sub-pixel rendering is not unique to TCL, Samsung NU8000 has it enabled on some modes as well.
The trouble with TCL , they didn't give the option to disable.
It is known to occur on 49/50, 55 and 65 inch sets, but there have been reports of people getting one with it disabled, Again, lottery ..
The 43 inch set was thought to be immune, but some has reported seeing it on there as well, not nearly as likely though.
It is possible that in the future, when access to the Factory service menu is discovered, Users may be able to disable it. (not something you'd wait for, if you don't like it , definitely buy something else).