The stories about the heavy bags Lee used have gotten twisted so much. I never heard of him using a 500ib bag. I do know for sure that he was once kicking a 200lb bag. He was getting the bag to swing towards him. He would kick the bag as it came towards him stopping the bag from swinging with his kick. someone asked him why he used a 200ib bag like that. He replied that if he could stop a 200lb bag coming at him he figured he could put a 400lb man on his A##.

...

500? No. 300, yes

500lb bag? That is tall tales stuff. But he was the master. Hell, he kicked Chuck Norris' butt.

Compared to say your typical sanda/sanshou kickboxer's side kick?

Ive studies Bruce Lee and various kickboxers from san shou including cung lee and well bruce has the best technique by far, however I dont believe it is far enough ahead technique wise to be significantly more powerful.

Take cung les side kick,, with his lead leg, it isnt that great, its not bad either, but you give him a side stepping run up (a luxory kickboxers dont have since their oppoents just get out the way and counter), and a heavybag which weighed as much as bruce lees heavybag (not much from his videos I can tell it wasnt very heavy at all) and you get cung to kick the bag, he will probably kick it as hard.

Am I right?

He has less technique than bruce but his technique isnt that bad, and hes bigger heavier etc I think he would make the same kinda impact as Bruce did.

This means since Cung Le never knocks anyone out with his side kick be it to the knee or body, that Bruce Lees side kick was equally ineffective in terms of doing damage and taking out an opponent.