I can't tell the difference in speed to be honest. But you are right about weights. Overdoing them does cost fighters speed and flexibility.
Of course Pac is one of the fastest on the planet, but just throwing your arms fast is easy (if you are a light small fighter) I was just saying it wasn't sped up. any lightweight amatuer fool can throw 40 punches in 12 seconds when they aren't trying to hit somebody world class http://youtu.be/WzqJNISfSjs http://youtu.be/c95Q6NZhR1Q
not just that planting with the thighs and turning into it that is "conventional technique", that leaping stepping forward pushing through the air from his toes without planting that used to make him overextend and look clumsy (in the 1st morales fight he was all over the place), he got much better at it.
Yes you're right the speed is clearly there but the balance is a different story Pacman throws fast punches but maintains his balance I doubt that man in the Vid could catch a punch while doing that
??? I can name 2 off the top of my head. Mosley, SRR If the weight is fully shifted to the arm/fist during a straight shot there will be a tendency to go off balance, thus youll see their feet readjust to compensate for the momentum.