You can definitely notice contrast levels, peak brightness, viewing angles and local dimming performance, especially in HDR. Not even notice, they are easily measurable. Rtings does that, just like many other good reviewing sites. Objectively, you're indeed being incredibly naive if you think this is unnoticeable, and that's putting it mildly because I have been warned my mods already. Go and buy your cheap TVs. Enjoy them for what they are worth. If you wanna participate, do some basic research first before shedding your gyaan.