Duran was pretty intimidating. Two stories verify this. One is when SRL was watching a Duran fight De Jesus and Jackie Gleason was in front of him. He (SRL being a big fan) said Jackie how's it going man, I'm probably going to be fighting that guy in the future. And Jackie looks at him and says, "don't do it son, the guy will kill you." SRL said he never watched the Honeymooners again. Another story which occurred in Montreal is that a reporter asked Frazier, who Duran reminded him of, and thought the answer would be him, Frazier. Instead Frasier answers "Charles Manson"
There's another story about Duran knocking out a horse when he was about 16, but accounts vary slightly. Some say it was a bet, whereby if he could do it him and his friends could drink all night and the bar bill would be waived. Duran himself said it was a bet over a bottle of whiskey. Either way he succeeded but broke his finger in the process.
Duran and Monzon were as fire and ice....Duran had those wild, Charles Manson eyes, Monzon had cold, expressionless reptilian kind of eyes...like a real psychopath, not like a wild man who would sooner than later, burn himself out.
Ya both were scary people, as was a prime Foreman, a prime Liston who were in the mold of a Monzon and a prime Tyson, who was more along the lines of a Duran.
What JG said was right on here...except for Max Schmeling the first time...Louis himself said before the fight that would be his first loss, "he a cool man"..
Ice usually beat fire...in the case of duran anyway...Benitez was ice...and he was able to outbox Duran all night...if Roberto and Monzon were to fight, ice would have killed fire.
The opposite side to those Duran stories is ( according to a Bio I read on him ) Manny Steward picked up on the fact that Duran was intimidated by Tommy Hearns stare, so he told him to get as close to Roberto as possible and really put the stare on him in the pre fight build up.
Think of the question like this, you're in the roughest bar you've ever been in and suddenly you realize you've inadvertently offended the entire bar. They're all slowly closing in on you. With perfect timing your 2 buddies come out of the bathroom. Even though they know where you are you call out to them and gesture them over, just to let the bar know if they wanna beat you up they're gonna have to go through your pals. Who would you want to be backing you up? Tyson (So long as he keeps his mouth shut and does that MacNeeley stare). the 2nd guy could be so many but I'll go with Golota just because his eyes really do look crazy and he's a big guy.
Well one fought at 135 (Duran) the other at 154 (Benitez) and one was a middleweight (160) so yes, Monzon would beat Duran, but not because of his temperament, because of his size and ability. (ie a great middleweight will be a very great light weight)