Ebike Escape explains the difference between them and the one that is best for you.
The sensor detects cadence and determines if you’re spinning your pedals no matter how fast you spin on the motor or gear.
Sensors for torque detect how much pressure you are applying when pedaling. When you accelerate faster, the harder the motor works. Although the torque sensor takes an extra effort but it’s than regular bikes. Sensors for Cadence allow cyclists to conserve energy and simply spin the pedals while the bike will do the rest.
In the YouTube video there is no way to say that one is better over the other. It is all up to the user and what they would prefer. You should research the product thoroughly before you make a purchase. Additionally, you should take in the amount that you’d want to invest. If you aren’t able to make a significant effort the cadence sensor could spin automatically and without any effort.