Is it as good as the videos say it is? Or will it eventually become a weight for a trot line?

Quick disconnect?

Quick Con and Discon.

I bought one cause I absolutely hate hooking up PTO shafts.
It works depending on your implement. You still sometimes have to turn your implement shaft a bit to get the three slot holes to line up with the pins.
That's fine if you can easily turn the implement shaft. If you have an implement that you can't turn the shaft very easy it's no different than quick connects that already are common on lots of implements anyway.