Forgot to add.. motion interpolation it also increases input lag as the frames are added in post-processing. Which isn't good for gaming. Always set your TV to gaming mode if you have it. It will get rid any MI effects and use the best settings for lowest latency.

Maybe if looks fine if you're watching sport or something. I certainly wouldn't use it for movies or gaming.

Plasma a special case and is not interpolation.  The 600Hz in a Plasma TV is the Sub-Field Drive rate not the screen refresh rate.

The Screen refresh rate on a 600Hz Plasma TV is still 60Hz.

If you want a more detail explanation this article does a decent job

https://www.lifewire.com/what-is-a-sub-field-drive-1847853#:~:text=If%20a%20plasma%20TV%20has,rate%20is%20stated%20as%20600Hz.

Plasma because there no backlight it self emitting can appear smoother to a lot of people even through it still 60hz (not counting OLED).  It also has by far the best blacks pre OLED.  OLED through is even better then Plasma in this regard since they are also self emitting.  

You aren't getting 300, 600hz or 1200hz LCD panels.
You might get a 240hz panel if you spend allot of money for an extremely extremely high-end set. I stress the might, they aren't common.

Majority of Televisions are actually 60hz, but due to marketers being in charge, will conflate the spec sheet numbers to hype themselves up.

I found a neuroscience paper (quick google search) that states "we revealed that FS neurons in human association cortices (mostly temporal) could generate APs at a maximal mean frequency (Fmean) of 338 Hz and a maximal instantaneous frequency (Finst) of 453 Hz, and they increase with age."

Grain of salt and all that, but keep in mind that would be Neurons, I think the eyes themselves might be even slower. No way panel refresh rates of 600hz+ would be visually noticeable.

Someone correct me if im wrong.

Marketing rubbish. every time I see someone curious about a TV I always recommend this site.

https://www.rtings.com/