Mentzer was bigger, harder, more conditioned and balanced than any other BB out there at the 1980 Mr O, as anyone with eyes can clarly see for himself from that comparison shot
Only proves that you have a bias for his type of physique, because the pic does not show him to be quite as good.
I never liked his physique, especially the extreme lack of refinement and detail in areas like arms and chest. Also lacked shoulder to waist differential relative to both Schwarzenegger and Zane as can be seen in that pic, in addition to his lack of refinement, detail and aesthetics.
He was never quite as good as Robinson, Padilla or Fox, let alone Szkalak who beat him.
I did like the way he stood up to Schwarzenegger though; it demolishes the whole theory that Schwarzenegger propogates endlessly that he was always able to psyche out his opponents, which was largely made-up BS.