Yeah these discussion always get muddled because people are discussing different things and keep misunderstanding eachother. 
Anyway, big bodybuilders are very strong and very powerful, a lot of times muscularly stronger and even more powerful than top powerlifters. It's just that powerlifting, moving a weight from A to B, involves a lot more than muscular strength and power. It's angles, it's structure, it's technique, it's attitude.
But on a very basic level size = strength. 
no these discussions always get muddled because idiots who dont know shit about getting big chime in with bullshit about how "weight doesnt matter", "the muscle cant tell how much weight its lifting, just when it fails", "the key to getting big is hard work to failure" blah blah blah blah blah
NO
and we must come to a solid agreement on this so we can start spreading the truth ont his board and others... like gh15was at first confronted with so many detractors untill finally everyone saw the truth... we must do the same for training. yes, drugs are absolutely essential, yes some guys with insane genetics and lots of durgs can get huge by pumping their muscles, BUT anyone who is big is strong, and you have to be strong before you can be big, and thus the way to get big (if your not a guy with insane genetics and a ton of gear) is to POWERLIFT with bodybuilding form untill youve got beastly strength, then you can work on adding reps and sets.