There's a difference between bodybuilding and weightlifting...check out this vid of Kai Green - I'll Never be A Weightlifter. Heavier weight doesn't necessarily mean a bigger physique. Not taking into account diet/rest,etc...it would seem technique and feeling the muscles contract are more important than weight for muscle hypertrophy.

http://www.youtube.com/watch?v=m8wZNGL4iA4&feature=related

There are guys much bigger than me in my gym, but I know I'm just as strong or stronger than some of these bros. That's cool...they just have different intent. I like to lift for strength and athletics and they want to bodybuild.

We call those guys bitches! Lol jk bro there is a lot of talk about lifting heavy causes one to gain lots of dense strong muscle vs someone who doesn't lift as heavy. Who knows then you have body builders who lift heavy everyday and others that barely lift heavy at all. Comes down to genetics.