In the video both you and your opponent are trying to open the game and quickly start the rallies far from the table and the slow reaction isn't as obvious. Far from the table you have time to get into position and hit the ball properly.
The slow reaction time was most obvious for me when I:
- play close to the table - against (fast) serves and long/short pushes
- play against people standing close to the table blocking and hitting fast using the arm and not the whole body, I know a guy which can hit very hard with a very short arm movement
- had to quickly adjust the bat angle/speed against weird balls: nets, edges - is much easier to return these balls with a lighter setup
Basically, whenever you need fast reactions a heavy setup will make you slower, unless you are in a very good shape.
In all the above cases the heavy setup affects my game and I make unforced errors. With a light setup I feel the paddle like a continuation of my arm, no latency present.
Most of the recent rubbers are very heavy IMO, MAX MX-S and MX-P 50 are 75 gr uncut, that's why I try to buy blades under 85 gr.
If you decide to buy a new blade you can try tabletennis11 and ask for a specific weight.