measuring pixel response times, total system latency, slow motions of different displays

This youtuber says it’s a really noticeable jump from 240 to 500.
He has tested every single new high refresh rate panel and use scientific methodologies.

Have you actually tried some of these technologies ? I own a 240hz an have never seen above so I can’t talk. I can say that motion blur reduction technologies influences perceived smoothness a lot tho.